AzureBlob Class

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The AzureBlob class provides an easy to use interface to Microsoft's Azure Blob Storage service.

Syntax

cloudstorage.AzureBlob

Remarks

The AzureBlob class offers an easy-to-use API for the Microsoft Azure Blob Storage service. Capabilities include uploading and downloading blobs of all types, strong encryption support, container management, and more.

Authentication

Authentication is simple, set the Account property to the name of the Azure Storage account to operate against, and set the AccessKey property to an Azure access key associated with that account.

Alternatively, this class supports authentication via OAuth 2.0. First, perform OAuth authentication using the OAuth property to set the appropriate fields for the chosen ClientProfile and GrantType. Typically, the following fields should be set to the below values:

Below is a brief description of the different ClientProfile and GrantType values that are supported by this class. For a more in-depth description of what needs to be set, refer to the service documentation.

Application Profile

This profile encompasses the most basic grant types that OAuth supports. When this profile is set, all the requests and response handling is done by the class. Depending on the grant type, this may involve launching a browser so a user can login to authenticate with a authorization server. It may also involve starting an embedded web server to receive a response from a redirect.

To start the authentication and authorization process, the Authorize method should be called. If the authorization and authentication was successful, then the AccessToken field will be populated. Additionally, if a refresh token was provided the RefreshToken field will be populated as well. These values of the fields are for informational purposes. The class will also cache these tokens along with when the AccessToken will be expired. When a method that makes requests to the service provider is called or the Authorize method is called the class will automatically check to see if the access token is expired. If it is, it will then automatically try to get a new AccessToken. If the Authorize method was not used and user interaction would be required, the class will throw an error which can be caught. When user interaction is needed depends on what grant type is set in the GrantType field. To force the component to only check the access token when the Authorize method is called, the OAuthAutomaticRefresh configuration setting can be set to false.

A brief description of the supported values for the GrantType field are below. For more information, see the service documentation.

Authorization Code

When using the Authorization Code grant type, the class will use an authorization code to get an access token. For this GrantType the class expects a ClientId, ClientSecret, ServerAuthURL, and ServerTokenURL to be set. When the Authorize method is called, the component will start the embedded web server and launch the browser so the user can authorize the application. Once the user authorizes, the service provider will redirect them to the embedded web server and the class will parse the authorization code, setting the AuthorizationCode field, from the redirect. Immediately, the class will make a request to the token server to exchange the authorization code for an access token. The token server will return an access token and possibly a refresh token. If the RefreshToken field is set, or a refresh token is cached, then the class will not launch the browser and use the refresh token in its request to the token server instead of an authorization code.

blob.OAuth.ClientProfile = CloudOAuthClientProfiles.cocpApplication; blob.OAuth.GrantType = OAuthSettingsGrantTypes.cogtAuthorizationCode; blob.OAuth.ClientId = CLIENT_ID; blob.OAuth.ClientSecret = CLIENT_SECRET; blob.OAuth.AuthorizationScope = "https://{ACCOUNT}.blob.core.windows.net/user_impersonation"; blob.OAuth.ServerAuthURL = "https://login.microsoftonline.com/{TENANT_ID}/oauth2/v2.0/authorize"; blob.OAuth.ServerTokenURL = "https://login.microsoftonline.com/{TENANT_ID}/oauth2/v2.0/token"; blob.Authorize();

Implicit

Note: This grant type is considered insecure and should only be used when necessary.

When using the Implicit grant type, the class will request the authorization server to get an access token. For this GrantType the class expects a ClientId, ClientSecret, and ServerAuthURL to be set. When the Authorize method is called, the component will start the embedded web server and launch the browser so the user can authorize the application. Once the user authorizes, the service provider will redirect them to the embedded web server and the class will parse the access token from the redirect.

A disadvantage of the grant type is that can not use a refresh token to silently get a new access token. Most service providers offer a way to silently get a new access token. See the service documentation for specifics. This means the class will not be able to automatically get a fresh token once it expires.

Password

Note: This grant type is considered insecure and should only be used when necessary.

When using the Resource Owner Password Credentials grant type, the class will authenticate as the resource owner. This allows for the class to avoid user interaction. This grant type often has specific limitations put on it by the service provider. See the service documentation for more details.

For this GrantType the class requires OAuthPasswordGrantUsername, ClientSecret, and ServerTokenURL to be set. The ClientSecret should be set to the password of the account instead of a typical secret. In some cases, the ClientId also needs to be set. When the Authorize method is called, the component will make a request to the token server for an access token using the username and password. The token server will return an access token if the authentication was successful. When this access token is expired, the component will automatically (see above for detailed description) make a new request to get a fresh one.

Web Profile

External OAuth Support

Bearer ACCESS_TOKEN_VALUE

Assign this value to the Authorization property before attempting any operations. Setting the Authorization property will cause the class to ignore the values set in the OAuth property.

Consult the Azure Blob Storage service's documentation for more information about using OAuth authentication.

Usage

Once authenticated, you can start interacting with the Azure Blob Storage service. The following list shows some of the methods used to accomplish common tasks:

• Container management: ListContainers, GetContainerInfo, CreateContainer, DeleteContainer, GetContainerACL, SetContainerACL
• Blob management: ListBlobs, GetBlobInfo, UpdateBlobInfo, CreateBlob, CopyBlob, GetBlob, DeleteBlob, UndeleteBlob
• Block blob management: ListBlocks, PutBlock, PutBlockList
• Page blob management: ListPageRanges, PutPages, ClearPages, UpdatePageBlob
• Append blob management: AppendBlock

The class support much more than just the functionality described above; refer to the complete API, below, for more information.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

AccessKey Property (AzureBlob Class)

The Azure access key to use for authentication.

Syntax

public String getAccessKey();
public void setAccessKey(String accessKey);

Default Value

""

Remarks

This property specifies the Azure access key that should be used for authentication. It must be set before attempting any operations which connect to the server.

Both primary and secondary access keys are valid.

Note: this property's value is ignored if the Authorization property is populated.

This property is not available at design time.

AccessPolicies Property (AzureBlob Class)

A collection of access policies.

Syntax

public AzureAccessPolicyList getAccessPolicies();
public void setAccessPolicies(AzureAccessPolicyList accessPolicies);

Remarks

This collection holds a list of AzureAccessPolicy items.

This collection is populated anytime GetContainerACL is called; and its items are used anytime SetContainerACL is called.

This property is not available at design time.

Account Property (AzureBlob Class)

The Azure storage account name.

Syntax

public String getAccount();
public void setAccount(String account);

Default Value

""

Remarks

This property specifies the name of the Azure storage account to operate against. It must be set before attempting any operations which connect to the server.

This property is not available at design time.

Authorization Property (AzureBlob Class)

OAuth 2.0 Authorization Token.

Syntax

public String getAuthorization();
public void setAuthorization(String authorization);

Default Value

""

Remarks

This class supports authentication via OAuth 2.0. First, perform OAuth authentication using the OAuth property, using the OAuth class or a separate process. If using the OAuth property, then the Authorization property will not be used.

Bearer ACCESS_TOKEN

Note: if both this property and AccessKey are populated, this property takes precedence, and the class will use OAuth authentication instead of shared key authentication. The Account property must be set in either case.

BlobData Property (AzureBlob Class)

The data that was downloaded, or that should be uploaded.

Syntax

public byte[] getBlobData();
public void setBlobData(byte[] blobData);

Default Value

""

Remarks

This property is populated with blob data after calling GetBlob if SetDownloadStream and LocalFile are not set.

This property can also be set before calling AppendBlock, CreateBlob (for block blobs), PutBlock, or PutPages; its data will be uploaded if SetUploadStream and LocalFile are not set.

This property is not available at design time.

BlobDelimiter Property (AzureBlob Class)

The delimiter string to use when listing blobs.

Syntax

public String getBlobDelimiter();
public void setBlobDelimiter(String blobDelimiter);

Default Value

""

Remarks

If this property is non-empty when ListBlobs is called, any blobs whose names contain the same string between the specified Prefix and the first occurrence of the specified delimiter that follow will be rolled up into a "common prefix" element, which is returned in place of the individual blobs themselves.

The PrefixList event will fire once for each common prefix returned. If the StorePrefixList configuration setting is enabled, the class will also populate the PrefixCount and Prefix[i] configuration settings

Blob Namespace Traversal

By using the BlobDelimiter and Prefix properties in tandem, applications can effectively "traverse" a virtual hierarchy of blobs as if it were a filesystem. For example, assume that blobs with the following names exist within a container:

• MyCompany
• MyCompany/Department1
• MyCompany/Department2
• MyCompany/Department2/EmployeeA
• MyCompany/Department2/EmployeeB

With BlobDelimiter set to /, we can set Prefix to successively "deeper" values before calling ListBlobs for the following effect:

This property is not available at design time.

BlobMarker Property (AzureBlob Class)

A marker indicating what page of blobs to return next.

Syntax

public String getBlobMarker();
public void setBlobMarker(String blobMarker);

Default Value

""

Remarks

This property will be populated when ListBlobs is called if the results are paged and there are more pages. To list all blobs, continue to call ListBlobs until this property returns empty string.

Refer to ListBlobs for more information.

This property is not available at design time.

Blobs Property (AzureBlob Class)

A collection of blobs.

Syntax

public AzureBlobBlobList getBlobs();
public void setBlobs(AzureBlobBlobList blobs);

Remarks

This collection holds a list of AzureBlobBlob items.

Calling ListBlobs or GetBlobInfo will populate this collection.

This property is not available at design time.

Blocks Property (AzureBlob Class)

A collection of blocks.

Syntax

public AzureBlobBlockList getBlocks();
public void setBlocks(AzureBlobBlockList blocks);

Remarks

This collection holds a list of AzureBlobBlock items.

Calling ListBlocks or AddBlock will populate this collection; and its items are used anytime PutBlockList is called. Additionally, if the CreateBlob method is used to create a new block blob, and more than 256MB if upload data is provided, the class will use this collection as it automatically uploads the data; refer to CreateBlob for more information.

This property is not available at design time.

Container Property (AzureBlob Class)

Selects a container.

Syntax

public String getContainer();
public void setContainer(String container);

Default Value

""

Remarks

This property selects a container, by name, for the class to operate against. It must be set before attempting most operations.

Container Name Rules

Container names must adhere to the following rules:

• Must be 3 to 63 characters long.
• Must start with a letter or number; and may only contain letters, numbers, and hyphens.
• All letters much be lowercase. (For convenience, the class will automatically lowercase all letters in any value assigned to Container.)
• All hyphens must be immediately preceded and followed by a letter or number (consecutive hyphens are not allowed).

This property is not available at design time.

ContainerMarker Property (AzureBlob Class)

A marker indicating what page of containers to return next.

Syntax

public String getContainerMarker();
public void setContainerMarker(String containerMarker);

Default Value

""

Remarks

This property will be populated when ListContainers is called if the results are paged and there are more pages. To list all containers, continue to call ListContainers until this property returns empty string.

Refer to ListContainers for more information.

This property is not available at design time.

Containers Property (AzureBlob Class)

A collection of containers.

Syntax

public AzureBlobContainerList getContainers();

Remarks

This collection holds a list of AzureBlobContainer items.

Calling ListContainers or GetContainerInfo will populate this collection.

This property is read-only and not available at design time.

EncryptionAlgorithm Property (AzureBlob Class)

The encryption algorithm.

Syntax

public int getEncryptionAlgorithm();
public void setEncryptionAlgorithm(int encryptionAlgorithm);

Enumerated values:
  public final static int eaAES = 0;
  public final static int eaBlowfish = 1;
  public final static int eaCAST = 2;
  public final static int eaDES = 3;
  public final static int eaIDEA = 4;
  public final static int eaRC2 = 5;
  public final static int eaRC4 = 6;
  public final static int eaTEA = 7;
  public final static int eaTripleDES = 8;
  public final static int eaTwofish = 9;
  public final static int eaRijndael = 10;
  public final static int eaChaCha = 11;
  public final static int eaXSalsa20 = 12;

Default Value

0

Remarks

This property specifies the encryption algorithm to be used. The maximum allowable key size is automatically used for the selected algorithm. Possible values are:

EncryptionPassword Property (AzureBlob Class)

The encryption password.

Syntax

public String getEncryptionPassword();
public void setEncryptionPassword(String encryptionPassword);

Default Value

""

Remarks

If this property is populated when UploadFile or DownloadFile is called, the class will attempt to encrypt or decrypt the data before uploading or after downloading it.

The class uses the value specified here to generate the necessary encryption Key and IV values using the PKCS5 password digest algorithm. This provides a simpler alternative to creating and managing Key and IV values directly.

However, it is also possible to explicitly specify the Key and IV values to use by setting the EncryptionKey and EncryptionIV configuration settings. This may be necessary if, e.g., the data needs to be encrypted/decrypted by another utility which generates Key and IV values differently.

This property is not available at design time.

Firewall Property (AzureBlob Class)

A set of properties related to firewall access.

Syntax

public Firewall getFirewall();
public void setFirewall(Firewall firewall);

Remarks

This is a Firewall-type property, which contains fields describing the firewall through which the class will attempt to connect.

Idle Property (AzureBlob Class)

The current status of the class.

Syntax

public boolean isIdle();

Default Value

True

Remarks

This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.

This property is read-only.

LeaseId Property (AzureBlob Class)

The lease Id to include when making requests.

Syntax

public String getLeaseId();
public void setLeaseId(String leaseId);

Default Value

""

Remarks

This property specifies the lease Id to include when making requests. If non-empty, this property's value must be a GUID string formatted in one of the styles described by Microsoft's .NET Guid(string) constructor documentation. For example: dddddddd-dddd-dddd-dddd-dddddddddddd, where each d is a single case-insensitive hex digit.

The following table indicates whether this property should be populated when calling a method on a container or blob that has an active lease.

For methods in one of the "MUST" categories: if this property is empty, requests will fail if the container or blob has an active lease. For CreateBlob and CopyBlob, note that this property must be empty if the target blob does not yet exist.

For all methods listed above: if this property is populated, requests will fail if the container or blob doesn't have an active lease; or if it does, but the lease Id specified by this property does not match.

Finally, note that this property is used in a specific manner by the Lease method; refer to its documentation for more information.

This property is not available at design time.

LocalFile Property (AzureBlob Class)

The location of the local file.

Syntax

public String getLocalFile();
public void setLocalFile(String localFile);

Default Value

""

Remarks

This property specifies the location of a file on disk. This is used as the source file when calling AppendBlock, CreateBlob (for block blobs), PutBlock, or PutPages; and as the destination file when calling GetBlob.

Note: Setting this property to a non-empty value will discard any streams set using SetDownloadStream and SetUploadStream. Similarly, passing a non-null value to either of the aforementioned methods will clear this property.

LocalHost Property (AzureBlob Class)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

public String getLocalHost();
public void setLocalHost(String localHost);

Default Value

""

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

Metadata Property (AzureBlob Class)

A collection of metadata items.

Syntax

public AzureMetadataList getMetadata();
public void setMetadata(AzureMetadataList metadata);

Remarks

This collection holds a list of AzureMetadata items.

This collection is populated when GetBlobInfo or GetContainerInfo is called; and its items are used anytime UpdateMetadata is called. Additionally, its items may be used when CreateBlob, CreateSnapshot, CopyBlob, and/or PutBlockList are called, depending on how the various SendMetadata* configuration settings are set.

This property is not available at design time.

OAuth Property (AzureBlob Class)

This property holds the OAuth Settings.

Syntax

public OAuthSettings getOAuth();

Remarks

This property is used to define the necessary fields to authenticate with the service provider. See the introduction for more information.

This property is read-only and not available at design time.

OtherHeaders Property (AzureBlob Class)

Other headers as determined by the user (optional).

Syntax

public String getOtherHeaders();
public void setOtherHeaders(String otherHeaders);

Default Value

""

Remarks

This property can be set to a string of headers to be appended to the HTTP request headers created from other properties like ContentType and From.

The headers must follow the format Header: Value as described in the HTTP specifications. Header lines should be separated by CRLF ("\r\n") .

Use this property with caution. If this property contains invalid headers, HTTP requests may fail.

This property is useful for extending the functionality of the class beyond what is provided.

This property is not available at design time.

Overwrite Property (AzureBlob Class)

Whether to overwrite the local file, or remote blob.

Syntax

public boolean isOverwrite();
public void setOverwrite(boolean overwrite);

Default Value

False

Remarks

When calling DownloadFile, this property determines if LocalFile should be overwritten if it already exists.

When calling CreateBlob or CopyBlob, this property determines if the remote blob should be overwritten if it already exists.

PageRanges Property (AzureBlob Class)

A collection of page range items.

Syntax

public AzureRangeList getPageRanges();

Remarks

This collection holds a list of AzureRange items.

This collection is populated when ListPageRanges is called.

This property is read-only and not available at design time.

ParsedHeaders Property (AzureBlob Class)

This property includes a collection of headers returned from the last request.

Syntax

public HeaderList getParsedHeaders();

Remarks

This property contains a collection of headers returned from the last request. Whenever headers are returned from the server, the headers are parsed into a collection of headers. Each Header in this collection contains information describing that header.

MaxHeaders can be used to control the maximum number of headers saved.

This collection is indexed from 0 to size -1.

This property is read-only and not available at design time.

Prefix Property (AzureBlob Class)

A prefix used to restrict the results returned when listing blobs or containers.

Syntax

public String getPrefix();
public void setPrefix(String prefix);

Default Value

""

Remarks

This property, if non-empty, is used to restrict the results returned by ListBlobs or ListContainers to only the items whose names begin with the given value.

Blob Namespace Traversal

By using the BlobDelimiter and Prefix properties in tandem, applications can effectively "traverse" a virtual hierarchy of blobs as if it were a filesystem. For example, assume that blobs with the following names exist within a container:

• MyCompany
• MyCompany/Department1
• MyCompany/Department2
• MyCompany/Department2/EmployeeA
• MyCompany/Department2/EmployeeB

With BlobDelimiter set to /, we can set Prefix to successively "deeper" values before calling ListBlobs for the following effect:

This property is not available at design time.

Proxy Property (AzureBlob Class)

A set of properties related to proxy access.

Syntax

public Proxy getProxy();
public void setProxy(Proxy proxy);

Remarks

This property contains fields describing the proxy through which the class will attempt to connect.

QueryParams Property (AzureBlob Class)

Additional query parameters to be included in the request.

Syntax

public QueryParamList getQueryParams();
public void setQueryParams(QueryParamList queryParams);

Remarks

This is a collection of query parameters that will be added to the request. Parameters can be added via the AddQueryParam method.

Range Property (AzureBlob Class)

The range of bytes to request.

Syntax

public String getRange();
public void setRange(String range);

Default Value

""

Remarks

This property specifies the range of bytes to request from the server. If this property is non-empty when a GetBlob or ListPageRanges request is being constructed, a header like x-ms-range: bytes=Range will be added to the request, with Range substituted with the specified value.

There are two valid formats for this property's value:

• StartByte-
• StartByte-EndByte

Note: If the StartByte property is greater than zero when GetBlob is called (i.e., when a download is being resumed), and this property is non-empty, the class will automatically advance the StartByte value in the specified range by StartByte bytes when sending the x-ms-range header to the server. This ensures that the previously-downloaded data at the start of the specified range is not downloaded again when the download is resumed.

This property is not available at design time.

Snapshot Property (AzureBlob Class)

The blob snapshot to make requests against.

Syntax

public String getSnapshot();
public void setSnapshot(String snapshot);

Default Value

""

Remarks

This property can be set to the opaque DateTime value used to identify a particular blob snapshot before calling the following methods in order to make requests against the specified blob snapshot instead of the base blob:

• CopyBlob (to copy from a blob snapshot)
• DeleteBlob
• GetBlob
• GetBlobInfo
• GetLink (to build a link for a specific blob snapshot)
• ListPageRanges
• SendCustomRequest

Refer to the documentation of the methods listed above for more information.

This property is not available at design time.

SSLAcceptServerCert Property (AzureBlob Class)

Instructs the class to unconditionally accept the server certificate that matches the supplied certificate.

Syntax

public Certificate getSSLAcceptServerCert();
public void setSSLAcceptServerCert(Certificate SSLAcceptServerCert);

Remarks

If it finds any issues with the certificate presented by the server, the class will normally terminate the connection with an error.

You may override this behavior by supplying a value for SSLAcceptServerCert. If the certificate supplied in SSLAcceptServerCert is the same as the certificate presented by the server, then the server certificate is accepted unconditionally, and the connection will continue normally.

Note: This functionality is provided only for cases in which you otherwise know that you are communicating with the right server. If used improperly, this property may create a security breach. Use it at your own risk.

SSLCert Property (AzureBlob Class)

The certificate to be used during Secure Sockets Layer (SSL) negotiation.

Syntax

public Certificate getSSLCert();
public void setSSLCert(Certificate SSLCert);

Remarks

This property includes the digital certificate that the class will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the Encoded field to the encoded certificate. To select a certificate, use the store and subject fields.

SSLProvider Property (AzureBlob Class)

The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use.

Syntax

public int getSSLProvider();
public void setSSLProvider(int SSLProvider);

Enumerated values:
  public final static int sslpAutomatic = 0;
  public final static int sslpPlatform = 1;
  public final static int sslpInternal = 2;

Default Value

0

Remarks

This property specifies the SSL/TLS implementation to use. In most cases the default value of 0 (Automatic) is recommended and should not be changed. When set to 0 (Automatic), the class will select whether to use the platform implementation or the internal implementation depending on the operating system as well as the TLS version being used.

Possible values are as follows:

In most cases using the default value (Automatic) is recommended. The class will select a provider depending on the current platform.

When Automatic is selected, the platform implementation is used by default. When TLS 1.3 is enabled via SSLEnabledProtocols, the internal implementation is used.

SSLServerCert Property (AzureBlob Class)

The server certificate for the last established connection.

Syntax

public Certificate getSSLServerCert();

Remarks

This property contains the server certificate for the last established connection.

SSLServerCert is reset every time a new connection is attempted.

This property is read-only.

StartByte Property (AzureBlob Class)

The byte offset from which to resume the upload or download.

Syntax

public long getStartByte();
public void setStartByte(long startByte);

Default Value

0

Remarks

This property specifies the byte offset from which to resume a block blob upload using CreateBlob, or a download of any blob type using GetBlob. Refer to those methods' documentation for more information about resuming uploads and downloads.

When uploading from a stream, the class will always seek forward in the stream if the value of StartByte is greater than 0 when CreateBlob is called. Keep this in mind when resuming interrupted block blob uploads.

This property is not available at design time.

Timeout Property (AzureBlob Class)

The timeout for the class.

Syntax

public int getTimeout();
public void setTimeout(int timeout);

Default Value

60

Remarks

If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If Timeout is set to a positive value, the class will wait for the operation to complete before returning control.

The class will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If Timeout expires, and the operation is not yet complete, the class throws an exception.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

UseSSL Property (AzureBlob Class)

Whether to use SSL/TLS when connecting.

Syntax

public boolean isUseSSL();
public void setUseSSL(boolean useSSL);

Default Value

True

Remarks

This property specifies whether the class should use SSL/TLS when connecting.

This property is not available at design time.

AbortCopy Method (AzureBlob Class)

Aborts a copy operation.

Syntax

public void abortCopy(String destBlob, String copyId);

Remarks

This method aborts the copy operation identified by the given CopyId for the destination blob DestBlob in the container currently selected by Container.

Note that the destination blob will still exist after aborting a copy operation, but it will be empty.

AddBlock Method (AzureBlob Class)

Adds a block to the Blocks properties.

Syntax

public void addBlock(String id, int blockListType);

Remarks

This method adds a block to the Blocks collection. Id specifies the block's Id, and BlockListType specifies where the server should search for this block.

Block Ids must be Base64-encoded when sent to the server. By default, the class will automatically Base64-encode block Ids as they are sent, and Base64-decode them as they are received. This behavior can be configured using the EncodeBlockIds configuration setting.

All block Ids must be less than or equal to 64 bytes in length before being Base64-encoded. Additionally, all blocks Ids within a single block blob must be unique, and of the exact same length after Base64-encoding.

Valid values for BlockListType are:

AddMetadata Method (AzureBlob Class)

Adds a metadata item to the Metadata properties.

Syntax

public void addMetadata(String name, String value);

Remarks

This method adds a metadata item to the Metadata collection. Name specifies the name of the item, and Value specifies the value of the item.

Note that the class will automatically prepend x-ms-meta- to metadata item names (as necessary) when they are submitted to the server. Also note that while metadata item names are case-preserving, they are not case-sensitive.

AddQueryParam Method (AzureBlob Class)

Adds a query parameter to the QueryParams properties.

Syntax

public void addQueryParam(String name, String value);

Remarks

This method is used to add a query parameter to the QueryParams collection. Name specifies the name of the parameter, and Value specifies the value of the parameter.

All specified Values will be URL encoded by the class automatically. Consult the service documentation for details on the available parameters.

AppendBlock Method (AzureBlob Class)

Appends a block of data to an append blob.

Syntax

public void appendBlock(String appendBlob);

Remarks

This method appends a block of data to the specified AppendBlob in the container currently selected by Container. The block of data is immediately available as part of the append blob, which must already exist.

Up to 100MB (104857600 bytes) of data may be appended in a single block, and up to 50000 blocks may be appended to a single append blob.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

Authorize Method (AzureBlob Class)

Get the authorization string required to access the protected resource.

Syntax

public void authorize();

Remarks

This method is used to get an access token that is required to access the protected resource. The method will act differently based on what is set in the ClientProfile field and the GrantType field. This method is not to be used in conjunction with the Authorization property. It should instead be used when setting the OAuth property.

For more information, see the introduction section.

CalcAuthorization Method (AzureBlob Class)

Calculates the Authorization header based on provided credentials.

Syntax

public void calcAuthorization();

Remarks

This method calculates the Authorization value using the values provided in AuthScheme, User and Password.

In most cases this method does not need to be called. The class will automatically calculate any required authorization values when a method is called such as Get or Post.

This method may be useful in cases where the Authorization value needs to be calculated prior to sending a request.

ClearPages Method (AzureBlob Class)

Clears a range of pages in a page blob.

Syntax

public void clearPages(String pageBlob, long byteOffset, long pageCount);

Remarks

This method clears PageCount pages, from ByteOffset onwards, for the specified PageBlob in the container currently selected by Container.

ByteOffset must be a multiple of 512; i.e. ByteOffset % 512 == 0. PageCount must be a number between 1 and the number of pages in the page blob following ByteOffset (inclusive).

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

Config Method (AzureBlob Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

CopyBlob Method (AzureBlob Class)

Copies a blob.

Syntax

public String copyBlob(String srcBlob, String destBlob, String destContainer);

Remarks

This method copies the specified SrcBlob (in the container currently selected by Container) to the specified DestBlob in DestContainer. If this method finishes successfully, it will either return an asynchronous copy Id, or an empty string (if the copy has finished already).

If Snapshot is non-empty, the specified snapshot of SrcBlob will be used as the copy source. In this case, DestBlob may be the same blob as SrcBlob to "promote" the snapshot, copying its contents back to the base blob.

If DestContainer is empty, the current value of Container is used instead. If DestContainer in non-empty, the value will automatically be lowercased when preparing the request.

If DestBlob already exists, and is the same type of blob as SrcBlob, then it will be overwritten if Overwrite is enabled. However, any snapshots associated with the existing blob are retained.

If DestBlob already exists and has an active infinite-duration lease, its lease Id must be specified using LeaseId, or the request will fail. (If it exists and has an active fixed-duration lease, the request will always fail.)

If the SendMetadataOnCopy configuration setting is enabled when this method is called, all items in the Metadata collection will be sent in the copy request and applied to DestBlob. Otherwise, the server will copy the metadata items from SrcBlob to DestBlob.

If the request succeeds, this method will always populate the CopyId and CopyStatus configuration settings (and clear CopyProgress and CopyStatusDesc).

Asynchronous Copy Notes

As mentioned, this method will return a copy operation Id if the copy operation was started asynchronously. In this case, use the GetBlobInfo method to poll the DestBlob blob's information, which will cause the CopyStatus, CopyStatusDesc, and CopyProgress configuration settings to be refreshed.

A copy operation whose CopyStatus is still pending may also be aborted by passing the copy operation Id returned by this method (or later retrieved from CopyId) to the AbortCopy method. // Copy a blob to another location within the same container. string copyResult = azureblob.CopyBlob("important.zip", "secrets.zip", ""); // If the returned value *isn't* empty string, then we'll monitor the status of the // asynchronous copy operation by polling once every 2 seconds using GetBlobInfo(). if (!string.IsNullOrEmpty(copyResult)) { do { azureblob.GetBlobInfo("secrets.zip"); Console.WriteLine("Copy progress: " + azureblob.Config("CopyProgress")); } while (azureblob.Config("CopyStatus") == "pending"); }

CreateBlob Method (AzureBlob Class)

Creates a new blob of the specified type.

Syntax

public void createBlob(String blob, int blobType, long pageBlobSize);

Remarks

This method creates a new blob named Blob in the container currently selected by Container. BlobType specifies what type of blob should be created; valid values are: Possible values are:

Refer to Azure's Understanding block blobs, append blobs, and page blobs article for more information about blob types.

PageBlobSize is only used when BlobType is abtPageBlob (1); it is ignored otherwise.

If the specified blob already exists, and is the same type of blob as BlobType specifies, then it will be overwritten if Overwrite is enabled. However, any snapshots associated with the existing blob are retained.

If the specified blob already exists and has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

If the SendMetadata configuration setting is enabled when this method is called, all items in the Metadata collection will be sent along with the creation request.

Creating Block Blobs

Block blobs can be created either with or without data initially. In either case, after the block blob is created, its contents can be managed by uploading blocks with PutBlock and then committing a new block list using PutBlockList.

If upload data is present when this method is called to create a block blob, it will be uploaded in one of two ways. If the amount of data provided is less than or equal to the limit specified by the SimpleUploadLimit configuration setting (268435456 bytes (256MB), by default), it will be uploaded directly in the create blob request.

If more than SimpleUploadLimit bytes of data are provided, the class will first create the new block blob, and then upload the data by splitting it up into blocks (sized according to the FragmentSize configuration setting), uploading them individually, and then committing a new block list. To accomplish this, the class automatically makes calls to PutBlock and PutBlockList internally, tracks the blocks as they are uploaded using the Blocks collection, and tracks how much data has been uploaded using the StartByte property. The FragmentComplete event will fire after each block is uploaded.

If, during a block-based upload, any individual PutBlock request (or the PutBlockList request) fails, the upload can be resumed be calling this method again with the same parameters, so long as the Blocks and StartByte properties still hold the same information as they did when the upload was interrupted.

When a block-based upload completes successfully, StartByte is reset to 0, but the Blocks collection remains populated. This allows applications to easily inspect the Ids of the uploaded blocks, which the class generates automatically in the following GUID format: dddddddd-dddd-dddd-dddd-dddddddddddd (where each d is a single hex digit).

Creating Page Blobs

Unlike block blobs, no data can be uploaded when creating a page blob. However, the page blob's size (i.e., capacity) must be specified using PageBlobSize. A page blob's size must be a 512-byte-aligned; i.e. PageBlobSize % 512 == 0.

Once a page blob has been created, its contents can be manipulated using the PutPages and ClearPages methods.

Creating Append Blobs

Append blobs must also be created without uploading any data initially. After a page blob has been created, data can be appended to it using the AppendBlock method.

CreateContainer Method (AzureBlob Class)

Creates a new container.

Syntax

public void createContainer();

Remarks

This method creates a new container using the name specified by the Container property;

If the SendMetadata configuration setting is enabled when this method is called, all items in the Metadata collection will be sent along with the creation request.

Container Name Rules

Container names must adhere to the following rules:

• Must be 3 to 63 characters long.
• Must start with a letter or number; and may only contain letters, numbers, and hyphens.
• All letters much be lowercase. (For convenience, the class will automatically lowercase all letters in any value assigned to Container.)
• All hyphens must be immediately preceded and followed by a letter or number (consecutive hyphens are not allowed).

CreateSnapshot Method (AzureBlob Class)

Creates a new snapshot of a blob.

Syntax

public String createSnapshot(String blob);

Remarks

This method creates a new snapshot of the specified Blob in the container currently selected by Container, and returns the opaque DateTime value used to identify the newly-created snapshot.

If the SendMetadataOnSnapshot configuration setting is enabled when this method is called, all items in the Metadata collection will be sent in the request and applied to newly-created snapshot. Otherwise, the server will copy the metadata items from Blob to the snapshot.

If the specified blob has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

DeleteBlob Method (AzureBlob Class)

Deletes a blob.

Syntax

public void deleteBlob(String blob, int deleteAction);

Remarks

This method deletes the specified Blob in the container currently selected by Container. DeleteAction specifies how the delete operation should be handled; possible values are:

Alternatively, if Snapshot is non-empty, the specified snapshot of Blob is deleted, and DeleteAction is ignored.

If the current Azure Storage account, specified by Account, has a delete retention policy enabled for the Blob service, then this method will only soft-delete blobs (and snapshots). Soft-deleted blobs and snapshots can be listed by enabling the IncludeSoftDeleted configuration setting before calling ListBlobs, and can be undeleted at any point before their retention period expires by calling UndeleteBlob. This method can alternatively permanently delete blobs and snapshots by enabling the DeletePermanently configuration setting.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

DeleteContainer Method (AzureBlob Class)

Deletes a container.

Syntax

public void deleteContainer();

Remarks

This method deletes the container currently selected by Container. Note that, according to the Azure documentation, when a container is deleted its name cannot be reused for at least 30 seconds.

If the current Azure Storage account, specified by Account, has a delete retention policy enabled for the Blob service, then this method will only soft-delete containers. Soft-deleted containers can be listed by enabling the IncludeSoftDeleted configuration setting before calling ListContainers, and can be undeleted at any point before their retention period expires by calling UndeleteContainer.

If the specified container has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

GetBlob Method (AzureBlob Class)

Downloads a blob.

Syntax

public void getBlob(String blob);

Remarks

This methods downloads the specified Blob in the container currently selected by Container. If Snapshot is non-empty, the specified snapshot of Blob is downloaded instead. The Range property can be used to download a specific range of bytes from the blob.

If the specified blob has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

If a stream has been specified using SetDownloadStream, the blob data will be sent through it. If a stream is not specified, and LocalFile is set, the blob data will be saved to the specified location; otherwise, the blob data will be held by ResourceData.

To download and decrypt an encrypted blob, set EncryptionAlgorithm and EncryptionPassword before calling this method.

Download Notes

In the simplest use-case, downloading a blob looks like this: azureblob.LocalFile = "../MyData.zip"; azureblob.GetBlob(azureblob.Blobs[0].Name);

Resuming Downloads

The class also supports resuming failed downloads by using the StartByte property. If a download is interrupted, set StartByte to the appropriate offset before calling this method to resume the download. string downloadFile = "../MyData.zip"; azureblob.LocalFile = downloadFile; azureblob.GetBlob(azureblob.Blobs[0].Name); //The transfer is interrupted and GetBlob() above fails. Later, resume the download: //Get the size of the partially downloaded file azureblob.StartByte = new FileInfo(downloadFile).Length; azureblob.GetBlob(azureblob.Blobs[0].Name);

Resuming Encrypted File Downloads

Resuming encrypted file downloads is only supported when LocalFile was set in the initial download attempt.

If LocalFile is set when beginning an encrypted download, the class creates a temporary file in TempPath to hold the encrypted data until the download is complete. If the download is interrupted, DownloadTempFile will be populated with the path of the temporary file that holds the partial data.

To resume, DownloadTempFile must be populated, along with StartByte, to allow the remainder of the encrypted data to be downloaded. Once the encrypted data is downloaded it will be decrypted and written to LocalFile. azureblob.LocalFile = "../MyData.zip"; azureblob.EncryptionPassword = "password"; azureblob.GetBlob(azureblob.Blobs[0].Name); //The transfer is interrupted and GetBlob() above fails. Later, resume the download: //Get the size of the partially downloaded temp file azureblob.StartByte = new FileInfo(azureblob.Config("DownloadTempFile")).Length; azureblob.GetBlob(azureblob.Blobs[0].Name);

GetBlobInfo Method (AzureBlob Class)

Gets a blob's information and metadata.

Syntax

public void getBlobInfo(String blob);

Remarks

This method gets information and metadata for the specified Blob in the container currently selected by Container. If Snapshot is non-empty, information and metadata for the specified snapshot of Blob is retrieved instead.

Calling this method will fire the BlobList and MetadataList events, and will re-populate the Blobs and Metadata collection properties.

If the specified blob has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

GetContainerACL Method (AzureBlob Class)

Gets the stored access policies and public access level for a container.

Syntax

public int getContainerACL();

Remarks

This method retrieves the stored access policies and the public access level for the container currently selected by Container. The stored access policies are used to populate the AccessPolicies collection, and the public access level is returned directly. Possible values are:

If the specified container has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

GetContainerInfo Method (AzureBlob Class)

Gets a container's information and metadata.

Syntax

public void getContainerInfo();

Remarks

This method gets information and metadata for the container currently selected by Container.

Calling this method will fire the ContainerList and MetadataList events, and will re-populate the Containers and Metadata collection properties.

If the specified container has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

GetLink Method (AzureBlob Class)

Creates a link that provides access to a container, blob, or snapshot.

Syntax

public String getLink(String blob, String permissions, String startTime, String expiryTime);

Remarks

This method creates and returns a shared access signature (SAS), which is a link that provides access to a specific container, blob, or snapshot. The following table indicates which inputs must be provided to produce a link of the desired type:

Permissions specifies what permissions the SAS grants, in the form of an abbreviated permissions list. Refer to this section of Azure's "Create a Service SAS" article for more information about how to format this value.

StartTime and ExpiryTime specify the UTC start and end times of the SAS's validity interval. Refer to this section of Azure's "Create a Service SAS" article for more information about how to format these values.

StartTime may be empty, in which case the server will assume that the link is valid immediately. Permissions and ExpiryTime must both be non-empty, unless an si query parameter that references a stored access policy (which has corresponding non-empty values) is present in the QueryParams collection.

If any of the query parameters listed below are present in the QueryParams collection when this method is called, they will be included when creating the SAS. All other application-specified query parameters are ignored.

• Response headers: rscc, rscd, rsce, rscl, rsct
• IP address (single or range): sip
• Allowed HTTP protocol(s): spr
• Stored access policy ("signed identifier"): si

For more information about SAS links, refer to Azure's Create a Service SAS article.

GetUserDelegationKey Method (AzureBlob Class)

Requests a new user delegation key.

Syntax

public void getUserDelegationKey(String startTime, String expiryTime);

Remarks

This method requests a new user delegation key and populates UserDelegationKey with the returned information.

NOTE: This method is not currently implemented; it is reserved for future use.

Interrupt Method (AzureBlob Class)

This method interrupts the current method.

Syntax

public void interrupt();

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

Lease Method (AzureBlob Class)

Creates or manages a lease on a blob or container.

Syntax

public void lease(String blob, int leaseAction, String newLeaseId, int duration);

Remarks

This method creates or manages a lease on the container currently selected by Container (if Blob is empty), or on the specified Blob in that container.

LeaseAction specifies what action should occur. Possible values, and their effects, are:

• Acquire (0): Requests a new lease.
  • If no active lease currently exists, a new one is created and LeaseId is populated with the new lease's Id. If a non-empty value is passed for NewLeaseId, it is used; otherwise the server generates an Id.
  • If an active lease currently exists, its Id must be passed for NewLeaseId.
  • In either case, Duration is used to specify the length of time that the lease is valid for (see below).
• Renew (1): Renews the lease specified by LeaseId.
  • Leases can only be renewed while active or expired (and in the latter case, only if a different lease has not been acquired in the meantime).
  • Renewing an active lease will reset its expiration clock.
• Change (2): Changes the Id of the active lease specified by LeaseId to the one specified by NewLeaseId.
  • If this action is successful, the class will automatically set LeaseId to the value passed for NewLeaseId.
• Release (3): Releases the lease specified by LeaseId.
  • If this action is successful, the class will automatically clear LeaseId.
• Break (4): Breaks the current lease, either immediately or after a certain period of time (the "break period") according to the value passed for Duration.
  • The lease's Id is not required to break the lease.
  • If Duration is -1, fixed-length leases are broken after their remaining time elapses, and infinite-length leases are broken immediately.
  • Otherwise, Duration specified how many seconds (see below) the lease should continue before being broken. (For fixed-length leases, the lesser of this value and the lease's remaining time is used.)
  • If this action is successful, the LeaseBreakPeriod configuration setting is populated to indicate how long the lease's break period is.

If NewLeaseId is non-empty, if must be a GUID string formatted in one of the styles described by Microsoft's .NET Guid(string) constructor documentation. For example: dddddddd-dddd-dddd-dddd-dddddddddddd, where each d is a single case-insensitive hex digit.

The value passed for Duration is only used in the cases listed below; it is ignored otherwise.

• When LeaseAction is Acquire (0): Valid values for Duration are -1 (infinite), or a number of seconds between 15 and 60 (inclusive).
• When LeaseAction is Break (4): Valid values for Duration are -1 (unspecified), or a number of seconds between 0 and 60 (inclusive). 0 indicates the lease should be broken immediately, regardless of whether it is fixed- or infinite-length.

For more information about how leases work, refer to Azure's Lease Blob and Lease Container API documentation.

ListBlobs Method (AzureBlob Class)

Lists the blobs in a container.

Syntax

public void listBlobs();

Remarks

This method lists the blobs in the container currently selected by Container.

Before calling this method, the Prefix property may be set in order to restrict the results to only the items whose names begin with a given string. The MaxResults configuration setting may also be used to limit the number of results returned. The following properties and configuration settings can also be used to further tune the results returned; refer to their documentation for more information:

• BlobDelimiter
• IncludeSnapshots
• IncludeSoftDeleted
• IncludeUncommittedBlobs
• ListWithMetadata

Calling this method will fire the BlobList event once for each blob, and will also populate the Blobs collection. It may also fire the PrefixList and MetadataList events, and populate the PrefixCount and Prefix[i] configuration settings, depending on how the properties and configuration settings discussed above are set.

If there are still more blobs available to list when this method returns, the BlobMarker property will be populated. Continue to call this method until BlobMarker is empty to accumulate all pages of results in the Blobs collection. Alternatively, the AccumulatePages configuration setting can be disabled to clear the Blobs collection every time a page of results is returned.

Blob Namespace Traversal

By using the BlobDelimiter and Prefix properties in tandem, applications can effectively "traverse" a virtual hierarchy of blobs as if it were a filesystem. For example, assume that blobs with the following names exist within a container:

• MyCompany
• MyCompany/Department1
• MyCompany/Department2
• MyCompany/Department2/EmployeeA
• MyCompany/Department2/EmployeeB

With BlobDelimiter set to /, we can set Prefix to successively "deeper" values before calling ListBlobs for the following effect:

ListBlocks Method (AzureBlob Class)

Lists the blocks associated with a block blob.

Syntax

public void listBlocks(String blockBlob, int blockListType);

Remarks

This method lists the blocks associated with the specified BlockBlob in the container currently selected by Container. BlockListType indicates which block list(s) the server should return results from; possible values are:

Alternatively, if Snapshot is non-empty, the committed blocks for the specified snapshot of BlockBlob are listed instead (and BlockListType is ignored).

Calling this method will fire the BlockList event once for each block, and will also repopulate the Blocks collection.

ListContainers Method (AzureBlob Class)

Lists the containers in the blob storage account.

Syntax

public void listContainers();

Remarks

This method lists the containers in the Azure blob storage account specified by the Account property.

Before calling this method, the Prefix property may be set in order to restrict the results to only the items whose names begin with a given string. The MaxResults configuration setting may also be used to limit the number of results returned. The ListWithMetadata and IncludeSoftDeleted configuration settings can also be used to further tune the results returned.

Calling this method will fire the ContainerList event once for each container, and will also populate the Containers collection. It may also fire the MetadataList event, depending on how the ListWithMetadata setting is configured.

If there are still more containers available to list when this method returns, the ContainerMarker property will be populated. Continue to call this method until ContainerMarker is empty to accumulate all pages of results in the Containers collection. Alternatively, the AccumulatePages configuration setting can be disabled to clear the Containers collection every time a page of results is returned.

ListPageRanges Method (AzureBlob Class)

Lists the page ranges of a page blob.

Syntax

public void listPageRanges(String pageBlob);

Remarks

This method lists the allocated page ranges of the specified PageBlob in the container currently selected by Container. If Snapshot is non-empty, the allocated page ranges for the specified snapshot of PageBlob are listed instead.

The Range property can be used to restrict the results to only the page ranges within the specified range.

Calling this method will repopulate the PageRanges collection. Every page in a page blob is exactly 512 bytes in length; thus, the size of every range returned by this method will always be a multiple of 512.

Normally, ranges of pages that are not currently allocated (either because no data has been written to them, or because they've been cleared with ClearPages) will not be returned by this method. However, setting the PreviousSnapshot configuration setting to a non-empty value will cause the server to return a list of all pages that differ between that snapshot and the base PageBlob (or the later snapshot of PageBlob specified by Snapshot); refer to PreviousSnapshot for more information.

If the specified blob has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

PutBlock Method (AzureBlob Class)

Uploads a new block of data to a block blob.

Syntax

public String putBlock(String blockBlob, String blockId);

Remarks

This method uploads a new block of data with the given BlockId to the specified BlockBlob in the container currently selected by Container. The block of data is uploaded in an uncommitted state; it will not be available as part of the block blob until it is committed in a PutBlockList operation.

The Base64-encoded Id of the block is returned (if the EncodeBlockIds configuration setting is disabled, the same value as passed for BlockId is returned; see below for more information).

If the specified BlockBlob does not yet exist, it is created in an uncommitted state. If an uncommitted block with the specified BlockId is already associated with the specified BlockBlob, it is replaced.

Block Ids must be Base64-encoded when sent to the server. By default, the class will automatically Base64-encode block Ids as they are sent, and Base64-decode them as they are received. This behavior can be configured using the EncodeBlockIds configuration setting.

All block Ids must be less than or equal to 64 bytes in length before being Base64-encoded. Additionally, all blocks Ids within a single block blob must be unique, and of the exact same length after Base64-encoding.

Up to 100MB (104857600 bytes) of data may be uploaded in a single block, and up to 100000 uncommitted blocks may be associated with a block blob at any time.

If the block is successfully uploaded, the class will automatically call AddBlock to add an item to the Blocks collection. This behavior can be changed using the AutoAddBlocks configuration setting.

If BlockBlob already exists and has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

PutBlockList Method (AzureBlob Class)

Commits a list of data blocks to a block blob.

Syntax

public void putBlockList(String blockBlob, String blockList);

Remarks

This method commits the blocks of data specified by the Blocks collection to the specified BlockBlob in the container currently selected by Container. Up to 50000 blocks may be committed to a single block blob at any time.

The BlockList parameter can optionally be passed a non-empty list of blocks to commit in order to repopulate the Blocks collection before building the request. This allows applications to build an entire block list and then commit it in a single call, rather than manipulating the Blocks collection directly, or calling AddBlock.

The value supplied should contain a comma-separated list of strings like {BlockListType}:{BlockId}, where {BlockListType} is either C, U, or L to specify whether the server should search for a block with the associated Id in BlockBlob's committed block list, uncommitted block list, or both (uncommitted; then committed, if necessary). If necessary, the BlockListStringSeparator configuration setting can be used to change the separator string used when parsing the value.

If BlockList is empty, the current items in the Blocks collection will remain unchanged.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

Note: By default, the class will automatically retrieve and re-submit the BlockBlob's current properties and metadata (if it exists) when this method is called, since Azure would clear them otherwise.

However, if one or more x-ms-blob-* headers are present in OtherHeaders when this method is called, the class will send them rather than re-submitting any of the retrieved blob properties. Similarly, if the SendMetadataOnPutBlockList configuration setting is enabled, the class will send the metadata items currently present in the Metadata collection instead of those retrieved from the server.

PutPages Method (AzureBlob Class)

Uploads a range of pages to a page blob.

Syntax

public void putPages(String pageBlob, long writeOffset);

Remarks

This method uploads a range of pages to the specified PageBlob in the container currently selected by Container, starting at the byte offset specified by WriteOffset. The uploaded data is immediately available as part of the page blob, which must already exist.

The upload data's size, in bytes, must be a multiple of 512 no larger than 4MB (4194304 bytes). The value passed for WriteOffset must also be a multiple of 512; WriteOffset % == 0.

Note that writing a page full of zeros will not actually clear said page, so it will still incur data storage charges. It is recommended that applications avoid writing pages that only contain zeros, or clear such pages using the ClearPages method.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

Reset Method (AzureBlob Class)

Resets the class to its initial state.

Syntax

public void reset();

Remarks

This method resets the class to its initial state.

SendCustomRequest Method (AzureBlob Class)

Sends a custom request to the Azure Blob Storage service.

Syntax

public void sendCustomRequest(String httpMethod, String blob, String requestBody);

Remarks

This method can be used to send arbitrary requests to the Azure Blob Storage service.

Valid values for HttpMethod are:

• GET (default if empty)
• HEAD
• POST
• PUT
• DELETE

The Blob and RequestBody parameters may be empty if not needed.

Usage

When this method is called, the class does the following:

1. Builds a request URL, including query parameters, using the following:
   • UseSSL
   • Account (must be non-empty)
   • Container (if non-empty)
   • Blob (if non-empty)
   • Snapshot (if both it and Blob are non-empty)
   • QueryParams
2. Adds request headers from:
   • APIVersion
   • LeaseId (if non-empty)
   • IfMatch (if non-empty)
   • OtherHeaders
3. Authenticates the request using Authorization (if non-empty), or AccessKey (in which case the request is signed).
4. Sends the request, including RequestBody if non-empty.
5. Stores the response headers in the ParsedHeaders collection; and the response body in the stream specified using SetDownloadStream, the specified LocalFile, or BlobData (using the same logic as GetBlob).

If the response body is XML data, the XPath, XText, and other X* configuration settings can then be used to navigate and extract information from it.

SetContainerACL Method (AzureBlob Class)

Sets the stored access policies and public access level for a container.

Syntax

public void setContainerACL(int publicAccess);

Remarks

This method sets the stored access policies and the public access level for the container currently specified by Container. The items in the AccessPolicies collection determine the new set of stored access policies, and PublicAccess determines the new public access level. Possible values are:

Note that it is not possible to do a partial update of stored access policies. That is, all stored access policies currently associated with the container will be replaced with the stored access policies sent in the request. To prevent data loss, applications should call GetContainerACL to retrieve the container's current stored access polices, and then add/modify/remove them as desired, before using this method.

If the specified container has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified.

SetDownloadStream Method (AzureBlob Class)

Sets the stream to which downloaded data will be written.

Syntax

public void setDownloadStream(java.io.OutputStream downloadStream);

Remarks

If a download stream is set before data is downloaded, the downloaded data will be written to the stream. The stream should be open and normally set to position 0.

Note: Passing a non-null value for DownloadStream will cause LocalFile to be cleared. Similarly, setting LocalFile to a non-empty value will discard any stream set using this method.

SetUploadStream Method (AzureBlob Class)

Sets the stream from which data is read when uploading.

Syntax

public void setUploadStream(java.io.InputStream uploadStream);

Remarks

If an upload stream is set before data is uploaded, the content of the stream will be read by the class and uploaded to the server. The stream should be open and normally set to position 0.

Note: Passing a non-null value for UploadStream will cause LocalFile to be cleared. Similarly, setting LocalFile to a non-empty value will discard any stream set using this method.

UndeleteBlob Method (AzureBlob Class)

Undeletes a soft-deleted blob.

Syntax

public void undeleteBlob(String blob);

Remarks

This method undeletes the specified soft-deleted Blob in the container currently selected by Container. If any soft-deleted snapshots are associated with the specified blob, they are also undeleted (note that this also works if the blob itself has not been soft-deleted).

Refer to DeleteBlob for more information about soft-deleting blobs.

UndeleteContainer Method (AzureBlob Class)

Undeletes a soft-deleted container.

Syntax

public void undeleteContainer(String container, String deletedVersion);

Remarks

This method undeletes the specified soft-deleted Container with the supplied DeletedVersion. If any soft-deleted blobs and snapshots are associated with the specified container, they are also undeleted, but note that soft-deleted blobs can only be restored in this manner if the container itself was also deleted.

Refer to DeleteContainer for more information about soft-deleting containers.

UpdateBlobInfo Method (AzureBlob Class)

Updates a blob's information.

Syntax

public void updateBlobInfo(String blob);

Remarks

This method updates the information of the specified Blob in the container currently selected by Container.

There must be an AzureBlobBlob collection whose Name field matches the specified Blob name (and whose Snapshot field is empty) before this method is called.

When this method is called, the values of the following fields on the aforementioned item are sent to the server (note that the last two are indexed configuration settings):

• ContentDisposition
• ContentEncoding
• ContentMD5
• ContentType
• BlobCacheControl[i]
• BlobContentLanguage[i]

Note that it is not possible to do a partial update of a blob's information. That is, all of the blob's current values for the aforementioned fields will be replaced with the values sent in the request. To prevent data loss, applications should call GetBlobInfo to retrieve the blob's current information, and then modify it as desired, before using this method.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

UpdateMetadata Method (AzureBlob Class)

Sets the metadata for a blob or container.

Syntax

public void updateMetadata(String blob);

Remarks

This method sets the metadata for the container currently selected by Container (if Blob is empty), or for the specified Blob in that container, to the items currently held by the Metadata collection.

Note that it is not possible to do a partial metadata update. That is, all metadata currently associated with the blob or container will be replaced with the metadata sent in the request. To prevent data loss, applications should call GetBlobInfo or GetContainerInfo to retrieve the blob or container's current metadata, and then modify it as desired, before using this method.

When setting the metadata of a container that has an active lease, a lease Id may optionally be specified using LeaseId; the request will only succeed if the correct lease Id is specified. When setting the metadata of a blob that has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

UpdatePageBlob Method (AzureBlob Class)

Updates a page blob's size and/or sequence number.

Syntax

public void updatePageBlob(String pageBlob, long newSize, int sequenceNumAction, long newSequenceNum);

Remarks

This method updates the size and/or sequence number of the specified PageBlob in the container currently selected by Container.

NewSize must either be -1 (to keep the page blob's current size), or a multiple of 512; i.e. NewSize % 512 == 0. If NewSize is less than the page blob's current size, all pages above the specified value are cleared.

SequenceNumAction determines how the page blob's sequence number should be changed; possible values are:

In cases where NewSequenceNum is used, it must be a value in the range 0 to 2^63 - 1, inclusive.

If the specified blob has an active lease, its lease Id must be specified using LeaseId, or the request will fail.

BlobList Event (AzureBlob Class)

Fires once for each blob returned when listing blobs.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void blobList(AzureBlobBlobListEvent e) {}
  ...
}

public class AzureBlobBlobListEvent {
  public String name;
  public String container;
  public int blobType;
  public String snapshot;
  public long contentLength;
  public String contentType;
  public String createdTime;
  public String modifiedTime;
  public String ETag;
  public boolean softDeleted;
  public boolean isLeased;
  public int leaseState;
}

Remarks

This event fires once for each blob returned when ListBlobs or GetBlobInfo is called.

Name is the name of the blob.

Container is the name of the blob's container.

BlobType is the blob's type. Possible values are:

Refer to Azure's Understanding block blobs, append blobs, and page blobs article for more information about blob types.

Snapshot is the snapshot identifier, if the current item represents a blob snapshot; empty otherwise.

ContentLength is the size of the blob's committed data in bytes, for block blobs and append blobs. For page blobs, its the capacity in bytes.

ContentType is the blob's content type. Always empty for uncommitted block blobs.

CreatedTime and ModifiedTime reflect the creation and last modified times of the blob, formatted according to RFC 1123. The latter is always empty for uncommitted block blobs.

ETag is the blob's ETag. Always empty for uncommitted block blobs.

SoftDeleted indicates whether the blob (or snapshot, if Snapshot is non-empty) has been soft-deleted.

IsLeased indicates whether the blob is currently leased. Always false if SoftDeleted is true and/or Snapshot is non-empty.

LeaseState reflects the lease state of the blob. Possible values are:

BlockList Event (AzureBlob Class)

Fires once for each block returned when listing blocks.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void blockList(AzureBlobBlockListEvent e) {}
  ...
}

public class AzureBlobBlockListEvent {
  public String id;
  public int blockType;
  public int size;
}

Remarks

This event fires once for each block returned when ListBlocks is called.

Id is the Id of the block.

BlockType reflects the block's type; possible values are:

• abktCommitted (0)
• abktUncommitted (1)

Size reflects the size of the block, in bytes.

ContainerList Event (AzureBlob Class)

Fires once for each container returned when listing containers.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void containerList(AzureBlobContainerListEvent e) {}
  ...
}

public class AzureBlobContainerListEvent {
  public String name;
  public String modifiedTime;
  public String ETag;
  public boolean isLeased;
  public int leaseState;
}

Remarks

This event fires once for each container returned when ListContainers or GetContainerInfo is called.

Name is the name of the container.

ModifiedTime reflects the last modified time of the container, formatted according to RFC 1123.

ETag is the container's ETag.

IsLeased indicates whether the container is currently leased.

LeaseState reflects the lease state of the container. Possible values are:

EndTransfer Event (AzureBlob Class)

This event fires when a document finishes transferring.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void endTransfer(AzureBlobEndTransferEvent e) {}
  ...
}

public class AzureBlobEndTransferEvent {
  public int direction;
}

Remarks

The EndTransfer event is fired when the document text finishes transferring from the server to the local host.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

Error Event (AzureBlob Class)

Fired when information is available about errors during data delivery.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void error(AzureBlobErrorEvent e) {}
  ...
}

public class AzureBlobErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

FragmentComplete Event (AzureBlob Class)

Fires after each block in an automatic block-based upload is complete.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void fragmentComplete(AzureBlobFragmentCompleteEvent e) {}
  ...
}

public class AzureBlobFragmentCompleteEvent {
  public int fragmentNumber;
  public int fragmentCount;
  public boolean interrupt; //read-write
}

Remarks

When CreateBlob is used to create a new block blob, and more than SimpleUploadLimit bytes of upload data is provided, the class will automatically split the upload data up into blocks to perform the upload. During the overall upload process, this event will fire after each block is uploaded, providing an indication of overall upload progress.

FragmentNumber is the number of the current block that has completed. This value starts at 1.

FragmentCount is the total number of blocks that will be uploaded.

Interrupt can be set to true to interrupt the upload. The upload may be resumed later.

Refer to CreateBlob for more information.

Header Event (AzureBlob Class)

Fired every time a header line comes in.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void header(AzureBlobHeaderEvent e) {}
  ...
}

public class AzureBlobHeaderEvent {
  public String field;
  public String value;
}

Remarks

The Field parameter contains the name of the HTTP header (which is the same as it is delivered). The Value parameter contains the header contents.

If the header line being retrieved is a continuation header line, then the Field parameter contains "" (empty string).

Log Event (AzureBlob Class)

Fired once for each log message.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void log(AzureBlobLogEvent e) {}
  ...
}

public class AzureBlobLogEvent {
  public int logLevel;
  public String message;
  public String logType;
}

Remarks

This event is fired once for each log message generated by the class. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the level of message. Possible values are as follows:

The value 1 (Info) logs basic information, including the URL, HTTP version, and status details.

The value 2 (Verbose) logs additional information about the request and response.

The value 3 (Debug) logs the headers and body for both the request and response, as well as additional debug information (if any).

Message is the log entry.

LogType identifies the type of log entry. Possible values are as follows:

• "Info"
• "RequestHeaders"
• "ResponseHeaders"
• "RequestBody"
• "ResponseBody"
• "ProxyRequest"
• "ProxyResponse"
• "FirewallRequest"
• "FirewallResponse"

MetadataList Event (AzureBlob Class)

Fires once for each metadata item returned when listing metadata.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void metadataList(AzureBlobMetadataListEvent e) {}
  ...
}

public class AzureBlobMetadataListEvent {
  public String container;
  public String blob;
  public String snapshot;
  public String name;
  public String value;
}

Remarks

This event fires once for each metadata item returned when GetBlobInfo or GetContainerInfo is called. If the ListWithMetadata configuration setting is enabled, it also fires as metadata for each individual blob or container is returned when ListBlobs or ListContainers is called.

Container is the name of the container that the blob is in (if Blob is non-empty), or that the metadata item is associated with (if Blob is empty).

Blob, if non-empty, is the name of the blob that the metadata item is associated with.

Snapshot, if non-empty, is the opaque DateTime value that identifiers the blob snapshot that the metadata item is associated with.

Name is the name of the metadata item, without the x-ms-meta- prefix.

Value the metadata item's value.

PrefixList Event (AzureBlob Class)

Fires once for each common prefix returned when listing blobs.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void prefixList(AzureBlobPrefixListEvent e) {}
  ...
}

public class AzureBlobPrefixListEvent {
  public String prefix;
}

Remarks

This event fires once for each common prefix returned when ListBlobs is called when BlobDelimiter is non-empty. Refer to BlobDelimiter for more information.

Prefix is the common prefix.

Progress Event (AzureBlob Class)

Fires during an upload or download to indicate transfer progress.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void progress(AzureBlobProgressEvent e) {}
  ...
}

public class AzureBlobProgressEvent {
  public int direction;
  public long bytesTransferred;
  public long totalBytes;
  public int percentDone;
}

Remarks

This event fires during an upload or download to indicate the progress of the transfer of the entire request. By default, this event will fire each time PercentDone increases by one percent; the ProgressStep configuration setting can be used to alter this behavior.

Direction indicates whether the transfer is an upload (0) or a download (1).

BytesTransferred reflects the number of bytes that have been transferred so far, or 0 if the transfer is starting (however, see note below).

TotalBytes reflects the total number of bytes that are to be transferred, or -1 if the total is unknown. This amount includes the size of everything in the request like HTTP headers.

PercentDone reflects the overall progress of the transfer, or -1 if the progress cannot be calculated.

Note: By default, the class tracks transfer progress absolutely. If a transfer is interrupted and later resumed, the values reported by this event upon and after resumption will account for the data that was transferred before the interruption.

For example, if 10MB of data was successfully transferred before the interruption, then this event will fire with a BytesTransferred value of 10485760 (10MB) when the transfer is first resumed, and then continue to fire with successively greater values as usual.

This behavior can be changed by disabling the ProgressAbsolute configuration setting, in which case the class will treat resumed transfers as "new" transfers. In this case, the BytesTransferred parameter will always be 0 the first time this event fires, regardless of whether the transfer is new or being resumed.

SSLServerAuthentication Event (AzureBlob Class)

Fired after the server presents its certificate to the client.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void SSLServerAuthentication(AzureBlobSSLServerAuthenticationEvent e) {}
  ...
}

public class AzureBlobSSLServerAuthenticationEvent {
  public byte[] certEncoded;
  public String certSubject;
  public String certIssuer;
  public String status;
  public boolean accept; //read-write
}

Remarks

During this event, the client can decide whether or not to continue with the connection process. The Accept parameter is a recommendation on whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string OK). If it is decided to continue, you can override and accept the certificate by setting the Accept parameter to True.

SSLStatus Event (AzureBlob Class)

Fired when secure connection progress messages are available.

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void SSLStatus(AzureBlobSSLStatusEvent e) {}
  ...
}

public class AzureBlobSSLStatusEvent {
  public String message;
}

Remarks

The event is fired for informational and logging purposes only. This event tracks the progress of the connection.

StartTransfer Event (AzureBlob Class)

This event fires when a document starts transferring (after the headers).

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void startTransfer(AzureBlobStartTransferEvent e) {}
  ...
}

public class AzureBlobStartTransferEvent {
  public int direction;
}

Remarks

The StartTransfer event is fired when the document text starts transferring from the server to the local host.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

Transfer Event (AzureBlob Class)

Fired while a document transfers (delivers document).

Syntax

public class DefaultAzureBlobEventListener implements AzureBlobEventListener {
  ...
  public void transfer(AzureBlobTransferEvent e) {}
  ...
}

public class AzureBlobTransferEvent {
  public int direction;
  public long bytesTransferred;
  public int percentDone;
  public byte[] text;
}

Remarks

The Text parameter contains the portion of the document text being received. It is empty if data are being posted to the server.

The BytesTransferred parameter contains the number of bytes transferred in this Direction since the beginning of the document text (excluding HTTP response headers).

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

The PercentDone parameter shows the progress of the transfer in the corresponding direction. If PercentDone can not be calculated the value will be -1.

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

AzureAccessPolicy Type

An Azure storage access policy.

Remarks

This type represents an Azure storage access policy.

Fields

Constructors

public AzureAccessPolicy();

public AzureAccessPolicy( id,  permissions,  startTime,  expiryTime);

AzureBlobBlob Type

An Azure storage blob.

Remarks

This type represents an Azure storage blob.

Fields

Constructors

public AzureBlobBlob();

AzureBlobBlock Type

An Azure storage block.

Remarks

This type represents an Azure storage block. Blocks are the chunks of data that comprise block blobs.

Fields

Constructors

public AzureBlobBlock();

public AzureBlobBlock( id,  type);

AzureBlobContainer Type

An Azure storage container.

Remarks

This type represents an Azure storage container.

Fields

AzureMetadata Type

An Azure metadata item.

Remarks

This type represents an Azure metadata item.

Fields

Constructors

public AzureMetadata();

public AzureMetadata( name,  value);

AzureRange Type

An Azure byte range.

Remarks

This type represents an Azure byte range.

Fields

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

public Certificate();

public Certificate( certificateFile);

public Certificate( encoded);

public Certificate( storeType,  store,  storePassword,  subject);

public Certificate( storeType,  store,  storePassword,  subject,  configurationString);

public Certificate( storeType,  store,  storePassword,  encoded);

public Certificate( storeType,  store,  storePassword,  subject);

public Certificate( storeType,  store,  storePassword,  subject,  configurationString);

public Certificate( storeType,  store,  storePassword,  encoded);

Firewall Type

The firewall the class will connect through.

Remarks

When connecting through a firewall, this type is used to specify different properties of the firewall, such as the firewall Host and the FirewallType.

Fields

Constructors

public Firewall();

Header Type

This is an HTTP header as it is received from the server.

Remarks

When a header is received through a Header event, it is parsed into a Header type. This type contains a Field, and its corresponding Value.

Fields

Constructors

public Header();

public Header( field,  value);

OAuthSettings Type

The settings to use to authenticate with the service provider.

Remarks

Used to set give the class the necessary information needed to complete OAuth authentication.

Fields

Constructors

public OAuthSettings();

Proxy Type

The proxy the class will connect to.

Remarks

When connecting through a proxy, this type is used to specify different properties of the proxy, such as the Server and the AuthScheme.

Fields

Constructors

public Proxy();

public Proxy( server,  port);

public Proxy( server,  port,  user,  password);

QueryParam Type

A query parameter to send in the request.

Remarks

This type represents a query parameter to send in the request.

Fields

Constructors

public QueryParam();

public QueryParam( name,  value);

Config Settings (AzureBlob Class)

AzureBlob Config Settings

<firstlevel>
  <one>value</one>
  <two>
    <item>first</item>
    <item>second</item>
  </two>
  <three>value three</three>
</firstlevel>

{
  "firstlevel": {
    "one": "value",
    "two": ["first", "second"],
    "three": "value three"
  }
}

OAuth Config Settings