Zip Component

Properties Methods Events Config Settings Errors

The Zip component implements a PKZip-compatible Zip compressor and decompressor.

Syntax

IPWorksZip.Zip

Remarks

The component uses the Deflate algorithm specified in RFC 1951 for compression, and produces and reads output compatible with PKZip, WinZip, etc.

To create a new archive, first set the ArchiveFile property to the name of the archive to be created. Then, specify the files to be compressed either by invoking IncludeFiles, or by adding a new object to the Files collection and setting the values of the DecompressedName and CompressedName. fields. Finally, call the Compress method to create the archive.

To decompress an existing archive, set ArchiveFile to the name of the archive to be decompressed. The ExtractToPath property may be set, and then calling the ExtractAll method will decompress all files in the archive to this path.

For finer control, the Scan method should be used to read the file information stored in the archive. This will fill out the information in the Files collection. The values of DecompressedName may then be changed if desired. Finally, ExtractAll may be used to decompress the entire archive, or Extract may be used for finer control.

Data may be streamed out by setting WriteToProgressEvent to true. Then, the Progress event may be trapped to retrieve the data.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

Example (Extracting from an Archive)

ZipControl.ArchiveFile = "c:\temp.zip" ZipControl.ExtractToPath = "c:\extracted\" ZipControl.ExtractAll()

Property List

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


ArchiveFile	The name of the zip, gzip, tar, or jar archive.
CompressionLevel	The compression level to use.
CompressionMethod	The compression method to use.
EncryptionAlgorithm	The algorithm used to encrypt files written to the archive.
ExcludedFiles	A list of files to exclude.
ExtractToPath	A base path to decompress to.
Files	Collection of Zip archive files.
OverwriteFiles	Whether or not to overwrite files.
Password	A password for the zip archive.
RecurseSubdirectories	Whether or not to recurse into subdirectories.
ZipComment	The comment for the entire zip file.
ZipData	(Decompression only) The zip file contents as a byte array.

Method List

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


abort	Aborts the current operation.
appendFiles	Adds specified files to an existing archive.
compress	Creates the compressed archive.
config	Sets or retrieves a configuration setting.
delete	Deletes one or more files from an existing archive.
extract	Extracts a single file, directory, or group of files, from the archive.
extractAll	Extracts all files from the compressed archive.
includeFiles	Specifies that the indicated files should be added to the archive.
reset	Resets the component.
scan	Scans the compressed archive.
setArchiveInputStream	The stream to read the zip, tar, jar, or gzip archive from.
setArchiveOutputStream	The stream to write the zip, tar, jar, or gzip archive to.
update	Will update certain files in an archive.

Event List

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


BeginFile	Fired before each file is processed.
EndFile	Fired after each file is processed.
Error	Information about non-fatal errors.
Overwrite	Fired whenever a file exists and may be overwritten.
Password	Fired when a file is encrypted, and the file's password is incorrect.
Progress	Fired as progress is made.

Config Settings

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


AESGenerateUniqueKeys	Whether to generate unique keys for each file encrypted.
CheckForFileLocks	If true, the component requests an exclusive lock during initialization.
CloseArchiveAfterCompress	Whether to close the archive after calling Compress.
CloseStreamAfterCompress	If true, the component will close the output stream after compression.
CompressionMethod	Used to set the method of compression.
EnableStreamingEncryption	Whether to allow streaming and encryption simultaneously.
Encoding	Encoding to be used for filenames.
ExcludedAttributes	Attributes of files to be excluded.
ExtractFilesOnly	Whether to only extract the files contained within the archive.
FileHashAlgorithm	The algorithm to use when computing the file hash.
ForceZip64Format	Whether to explicitly compress a Zip64 format archive.
MarkAsText	Whether to mark files as text files.
OverwriteReadonlyFiles	Whether to overwrite readonly files.
PreserveModifiedTime	Whether or not to preserve the original modified time on extracted files.
UseIBM437ASDefaultEncoding	Whether or not to use the IBM437 default encoding.
VerifyPassword	Check whether the specified Password can decrypt the archive without extracting files.
WriteToProgressEvent	Whether or not to write data to the Progress Event.
BuildInfo	Information about the product's build.
GUIAvailable	Tells the component whether or not a message loop is available for processing events.
LicenseInfo	Information about the current license.
MaskSensitive	Whether sensitive data is masked in log messages.
UseDaemonThreads	Whether threads created by the component are daemon threads.
UseInternalSecurityAPI	Tells the component whether or not to use the system security libraries or an internal implementation.

ArchiveFile Property (Zip Component)

The name of the zip, gzip, tar, or jar archive.

Syntax


public String getArchiveFile();


public void setArchiveFile(String archiveFile);

Default Value

Remarks

This property specifies the name of the archive to be read or written. This property is required when extracting files.

When Scan, Extract, or ExtractAll is invoked, the file specified by ArchiveFile will be opened for read. If the file does not exist, a trappable error will be generated.

When Compress is called, the file named by ArchiveFile will be written; if a file of this name already exists the Overwrite event will be fired. If ArchiveFile is set to the empty string (""), the archive will not be written to disk, and will be provided only through the Progress event.

The filename may be specified with or without a path. Paths may be relative or absolute, and should be specified in the format native to the host operating system. The filename should be specified with the appropriate extension (such as "zip"); an extension will not automatically be appended by the component.

If the file cannot be read, or written, as appropriate, a trappable error will be generated.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

Note: an archive already open for read may be closed by setting ArchiveFile to the empty string ("").

CompressionLevel Property (Zip Component)

The compression level to use.

Syntax


public int getCompressionLevel();


public void setCompressionLevel(int compressionLevel);

Default Value

Remarks

This property specifies the level of compression to be used, between 0 and 6. Higher values will cause the component to compress better; lower values will cause the component to compress faster. A value of 0 will store the file without compression.

Set the level of CompressionLevel in the BeginFile event to apply different levels of compression to different files.

CompressionMethod Property (Zip Component)

The compression method to use.

Syntax


public int getCompressionMethod();


public void setCompressionMethod(int compressionMethod);

Enumerated values:
  public final static int cmDeflate = 0;

  public final static int cmPPMd = 1;

  public final static int cmBzip2 = 2;

Default Value

Remarks

This property specifies the compression method to use. By default the component uses the Deflate compression method (a value of 0). Supported values are:

0 (cmDeflate - default)
1 (cmPPMd)
2 (cmBzip2)

EncryptionAlgorithm Property (Zip Component)

The algorithm used to encrypt files written to the archive.

Syntax


public int getEncryptionAlgorithm();


public void setEncryptionAlgorithm(int encryptionAlgorithm);

Enumerated values:
  public final static int eaDefault = 0;

  public final static int eaAESWeak = 1;

  public final static int eaAESStrong = 2;

  public final static int eaAESMaximum = 3;

Default Value

Remarks

The algorithm used to encrypt files written to the archive.

Note that files will only be encrypted if Password is set. By default the component will use standard zip encryption if Password is set, and will not encrypt data otherwise.

The component supports the use of AES, the Advanced Encryption Standard, as well as standard Zip encryption. The default encryption algorithm is the algorithm introduced in version 2.0 of the Zip specification, and is compatible with virtually all other zip utilities. However, this algorithm is considered weak and should not be used to protect sensitive data.

AES is a U.S. government standard cleared to protect even the most sensitive data. The file format used to create AES-encrypted files is designed to be compatible with WinZip 9.0. AES-encrypted files created by the component may or may not be compatible with other Zip utilities.

The component supports the use of AES with key lengths of 128, 192, or 256 bits. Note that even with the weakest (128-bit) keys AES is much more secure than standard Zip encryption.

If you use strong or maximum AES encryption the component will generate a unique salt value and cryptographic key for each file encrypted. If you use weak encryption the component will use the same salt for each file in the archive. If you are encrypting a large number of files this will have a substantial effect on performance. Set the AESGenerateUniqueKeys configuration setting to configure the salt generation independent of the key length.

If using AES encryption it is important to choose a good Password. For 128-bit keys it is recommended that your password be 32 characters long, and for 256-bit keys, 64 characters.

Important: Note that AES encryption only encrypts the contents of encrypted files within the Zip archive; it does not prevent an attacker from reading the names of files in the archive, or from adding or deleting files to or from the archive. To prevent this consider first storing your files in an unencrypted zip file, and then storing this zip file in another, AES-encrypted zip file.

Property values:


eaDefault	0
eaAESWeak	1
eaAESStrong	2
eaAESMaximum	3

ExcludedFiles Property (Zip Component)

A list of files to exclude.

Syntax


public String getExcludedFiles();


public void setExcludedFiles(String excludedFiles);

Default Value

Remarks

This property specifies files that should be excluded when Compress or Extract is invoked. When Compress is invoked, each value of DecompressedName in Files will be compared to ExcludedFiles, and each file will be excluded if the name matches. When Extract is called, each value of CompressedName in Files matching the parameter to Extract will be compared to ExcludedFiles, and will be excluded if appropriate. Calling the ExtractAll method will ignore this property and extract all files in the archive.

This property may be set to one or more filenames or directory names. Files may be specified with or without a path, and with or without wildcards. If a path is specified, files in the indicated directory will be excluded; subdirectories will be recursed into if RecurseSubdirectories is true. If no path is specified but wildcards are, matching files in all directories will be excluded. If a single filename without a path is specified, it must correspond exactly to the appropriate value of CompressedName or DecompressedName.

Directories should end with a slash ("/" or "\", as appropriate.) If a directory is specified, all files and subdirectories in the specified directory will be excluded.

A pipe character ("|") should be used to separate multiple file or directory names.

The following examples illustrate the use of the property:

Example

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.IncludeFiles("c:\test\*") ZipControl.ExcludedFiles = "*.tmp" ZipControl.Compress() Example

ZipControl.ArchiveFile = "c:\test.tar" ZipControl.Scan() ZipControl.ExcludedFiles = "*.bak | backup/" ZipControl.ExtractToPath = "c:\temp" ZipControl.Extract("*") As per the examples, the property should be specified differently for compression and decompression. When invoking Compress, the format of ExcludedFiles should correspond to that of the local file system. When invoking Extract the format should correspond to standard (UNIX) format, and should not contain drive letters or backslashes.

You may exclude files based on their attributes as well: See the ExcludedAttributes configuration setting for more information.

If the property is set to the empty string, no files will be excluded. This property is never reset automatically, so be sure to reset it manually if using a single instance of the component for both compression and extraction. Failure to do so may result in I/O errors or unexpected results.

ExtractToPath Property (Zip Component)

A base path to decompress to.

Syntax


public String getExtractToPath();


public void setExtractToPath(String extractToPath);

Default Value

Remarks

Setting the ExtractToPath property affects the operation of the Extract and ExtractAll methods. Setting this property to a nonempty string will cause all decompressed files to be written to the specified path. If pathnames are given in the values of DecompressedName they will be regarded as relative to ExtractToPath.

If the specified directory does not exist, it will be created when extraction is done.

ExtractToPath should always be specified in the format native to the host operating system, and with a trailing slash or backslash. If the path is specified otherwise, it will be immediately converted and stored in the converted format. For example, "/temp" would be immediately converted to "\temp\" on a Windows system.

Example (Extracting from an Archive)

ZipControl.ArchiveFile = "c:\temp.zip" ZipControl.ExtractToPath = "c:\extracted\" ZipControl.ExtractAll()

Example - Adding Files Dim i as Integer ZipControl.ArchiveFile = "c:\test.zip" ZipControl.Scan() For i = 0 to ZipControl.Files.Count - 1 ZipControl.Files(i).DecompressedName(i) = "c:\temp\" + ZipControl.Files(i).DecompressedName Next i ZipControl.ExtractToPath = "" ZipControl.ExtractAll() ZipControl.IncludeFiles("c:\extra\*") ZipControl.Compress()

Files Property (Zip Component)

Collection of Zip archive files.

Syntax


public ZIPFileList getFiles();


public void setFiles(ZIPFileList files);

Remarks

When a compressed archive is scanned or decompressed, the values of this collection are populated accordingly.

When creating a compressed archive, this property may be used to set the files to be stored. For each entry added to the collection, the DecompressedName field should be set to the name of the file to be decompressed, and the CompressedName field should be set to the filename to store in the archive.

Archives may also be created using the IncludeFiles method. Invoking the IncludeFiles method causes the values of this collection to be filled out. These values may then be changed directly if desired.

Please refer to the ZIPFile type for a complete list of fields.

OverwriteFiles Property (Zip Component)

Whether or not to overwrite files.

Syntax


public boolean isOverwriteFiles();


public void setOverwriteFiles(boolean overwriteFiles);

Default Value

True

Remarks

If this property is set to true, existing files will be overwritten when decompressing. When Extract or ExtractAll is called, each file specified in Files will be checked for existence. If a file exists, the Overwrite event will be fired, and the files will be overwritten if OverwriteFiles is set to true.

More precise control of which files should be overwritten may be gained by listening to the Overwrite event and altering its parameters when the event is fired.

This property only affects the operation of Extract and ExtractAll. When compressing files, ArchiveFile will always be overwritten unless the user specifies otherwise in the Overwrite event.

Password Property (Zip Component)

A password for the zip archive.

Syntax


public String getPassword();


public void setPassword(String password);

Default Value

Remarks

This property specifies the case-sensitive password used to encrypt or decrypt the archive. If set to an empty string, no password is used.

In this release, streaming out of encrypted archives is not supported. When compressing, WriteToProgressEvent must be set to false if Password is set.

Example (Compressing an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Password = "nsoftware" ZipControl.Compress()

RecurseSubdirectories Property (Zip Component)

Whether or not to recurse into subdirectories.

Syntax


public boolean isRecurseSubdirectories();


public void setRecurseSubdirectories(boolean recurseSubdirectories);

Default Value

True

Remarks

This property affects the behavior of IncludeFiles and Extract and the meaning of ExcludedFiles. If this property is set to true, IncludeFiles will recurse into all subdirectories whenever it performs a search on the file system.

Be sure RecurseSubdirectories is set to the appropriate value before invoking IncludeFiles, Extract, or Compress; changing the value of this property after method calls will not retroactively alter their effects.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

ZipComment Property (Zip Component)

The comment for the entire zip file.

Syntax


public String getZipComment();


public void setZipComment(String zipComment);

Default Value

Remarks

Specifies a global comment for the zip file. Set this property before invoking Compress to include a comment in the zip file. Read it after invoking Scan to read the zip comment.

ZipData Property (Zip Component)

(Decompression only) The zip file contents as a byte array.

Syntax


public byte[] getZipData();


public void setZipData(byte[] zipData);

Default Value

Remarks

Normally you should set ArchiveFile before invoking Scan or Extract. If you prefer to read the zip file from memory you may set ZipData instead. ZipData should be set to the entire contents of the zip file; this will allow you to read from the archive without writing any temporary files to disk.

If you would like to extract data from the archive without ever writing to disk you should also set WriteToProgressEvent to true, and after invoking Scan, you should set the value of DecompressedName for each file in the Files collection to an empty string. Then, when you invoke Extract (or ExtractAll) the data will be provided in the Progress event.

This property is write-only. Note that modifying a zip file stored in ZipData is not supported, so Append, Delete, etc., will throw exceptions.

This property is not available at design time.

Abort Method (Zip Component)

Aborts the current operation.

Syntax

public void abort();

Remarks

Abort may be used to immediately interrupt compression or decompression. Any files partially written by the component will be deleted.

In case Append or Delete is aborted the archive will be left in its original state.

AppendFiles Method (Zip Component)

Adds specified files to an existing archive.

Syntax

public void appendFiles();

Remarks

All files contained in the Files collection will be appended to the archive specified by ArchiveFile.

When AppendFiles is called, only those files which are to be added to the archive must exist inside the collection. Note that if you call Scan or Extract, you must empty the collection before adding files to the collection to be appended.

After the file is added, the collection will be updated appropriately.

This method may only be used to add files to an existing archive. To add files to a new archive, the IncludeFiles and Compress methods should be used.

Compress Method (Zip Component)

Creates the compressed archive.

Syntax

public void compress();

Remarks

Invoking Compress creates the archive specified by ArchiveFile. When the method is called, all files specified by the DecompressedName field of the Files collection will be compressed and written to ArchiveFile.

The compressed data may be streamed out by setting WriteToProgressEvent to true. If streaming is enabled the compressed data will also be provided via the Progress event. If ArchiveFile is set to an empty string the archive will be written only to this event.

The files to compress are specified in the Files collection. The file names are specified by CompressedName and DecompressedName. These should be specified before invoking Compress, either manually or by invoking IncludeFiles.

The BeginFile and EndFile events will be fired as files are processed, and the Progress event will be fired as data is compressed.

Existing files will be overwritten by the component if OverwriteFiles is set to true. Finer control over which files are overwritten may be gained by trapping the Overwrite event.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

Config Method (Zip Component)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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.

Delete Method (Zip Component)

Deletes one or more files from an existing archive.

Syntax

public void delete(String filenames);

Remarks

Delete deletes one or more files from an existing archive, without reprocessing the compressed data. The archive will be opened immediately, and the file(s) will immediately be removed permanently from the archive.

The list of filenames should be specified exactly as when calling Extract:

Filenames may be set to one or more filenames or directory names. Files may be specified with or without a path, and with or without wildcards. If a path is specified, files in the indicated directory will be affected; subdirectories will be recursed into if RecurseSubdirectories is true. If no path is specified but wildcards are, matching files in all directories will be affected. If a single filename without a path is specified, it must correspond exactly to the appropriate value of CompressedName.

Directories should end with a slash ("/"). If a directory is specified, all files and subdirectories in the specified directory will be affected.

A pipe character ("|") should be used to separate multiple file or directory names. Alternatively, the method may be invoked repeatedly.

The ExcludedFiles property may be used to further limit the files to be deleted. When Delete is used to delete a directory or match wildcards, each file to be deleted is first compared against ExcludedFiles, and any files marked as excluded will not be deleted. When Delete is used to delete a single file, the value of ExcludedFiles will be ignored.

When the method is invoked, the Scan method will first be invoked, if it has not been invoked already. Note that if IncludeFiles has been invoked, or if the values of CompressedName and DecompressedName for each file in the Files collection have been set, this information will be reset by the call to Scan.

When deleting multiple files, the component will operate most efficiently if all filenames are passed to Delete in a single invocation of the method. Invoking Delete repeatedly on large archives is not recommended.

Invoking Delete will only remove files from ArchiveFile; it will not delete the files from the disk.

Example

ZipControl.ArchiveFile = "c:\\test.zip" ZipControl.Delete("default_readme.txt"); ZipControl.Append("\\mydir\\my_readme.txt", "my_readme.txt")

Extract Method (Zip Component)

Extracts a single file, directory, or group of files, from the archive.

Syntax

public void extract(String filenames);

Remarks

Extract extracts one or more files from the archive. The file(s) will be extracted to the directory specified by ExtractToPath, and given the names found in the archive or specified by the DecompressedName of the file in the Files collection.

Directories should end with a slash ("/"). If a directory is specified, all files and subdirectories in the specified directory will be affected.

A pipe character ("|") should be used to separate multiple file or directory names. Alternatively, the method may be invoked repeatedly.

The ExcludedFiles property may be used to further limit the files to be extracted. When Extract is used to extract a directory or match wildcards, each file to be extracted is first compared against ExcludedFiles, and any files marked as excluded will not be extracted. When Extract is used to extract a single file, the value of ExcludedFiles will be ignored.

To extract all files in the archive, the ExtractAll method may be used.

The BeginFile and EndFile events will be fired before and after each file is extracted, and the Progress event will be fired as the data is extracted. If WriteToProgressEvent is set to true, the decompressed data will be streamed out through the Progress event.

Example

ZipControl.ArchiveFile = "c:\test.tar" ZipControl.ExcludedFiles = "*.bak | backup/" ZipControl.ExtractToPath = "c:\temp" ZipControl.Extract("*") Example ZipControl.ArchiveFile = "c:\test.zip" ZipControl.ExcludedFiles = "" ZipControl.ExtractToPath = "c:\temp" ZipControl.Extract("code/") Example ZipControl.ArchiveFile = "c:\test.jar" ZipControl.ExcludedFiles = "*.txt" ZipControl.ExtractToPath = "c:\" ZipControl.Extract("* | docs/readme.txt")

ExtractAll Method (Zip Component)

Extracts all files from the compressed archive.

Syntax

public void extractAll();

Remarks

ExtractAll extracts all files from the archive. The file(s) will be extracted to the directory specified by ExtractToPath, and given the names found in the archive or specified by the DecompressedName field of the file in the Files collection.

If Scan has not been invoked when ExtractAll is called, Scan will automatically be invoked, and the Files collection will be set to the values found in the archive. To manually set the decompressed filenames, Scan should be invoked before setting the DecompressedName field.

Invoking this method is equivalent to setting ExcludedFiles to the empty string, and then invoking Extract with "*" as the argument. Calling this method will cause the ExcludedFiles property to be ignored; to extract all files except those specified by ExcludedFiles, call the Extract method with the wildcard "*" as the method parameter instead of calling this method.

Example (Extracting from an Archive)

ZipControl.ArchiveFile = "c:\temp.zip" ZipControl.ExtractToPath = "c:\extracted\" ZipControl.ExtractAll()

IncludeFiles Method (Zip Component)

Specifies that the indicated files should be added to the archive.

Syntax

public void includeFiles(String filenames);

Remarks

IncludeFiles may be used before Compress, to specify the files to be compressed. Invoking this method populates the Files collection accordingly.

Invoking the method does not create or alter the archive.

The argument should be a pipe ("|") -delimited sequence of one or more filenames. The filenames should be specified with paths if necessary, so that the files may be found on the local file system. The filenames will be stored as is in the DecompressedName field, and without a pathname in the CompressedName field of the Files collection.

Filenames may include the wildcards '?', '*', and '[ .. ]'. '?' will match any single character, and '*' will match an arbitrary sequence of characters. '[ .. ]' may be used to match any of the characters inside, or a range, such as '[a-z]'. A '\' can be used to escape wildcard characters.

If wildcards are specified, the file system will be scanned and all files matching the specified mask will be added. Moreover, subdirectories will be recursed into if RecurseSubdirectories is set to true. When recursing into subdirectories, relative path information will be stored in CompressedName field of the Files collection.

The ExcludedFiles may be used to limit the files to be compressed. This property is checked when Compress is invoked, rather than when IncludeFiles is invoked, so this property may be set before or after invoking IncludeFiles.

Note that invoking IncludeFiles will not reset the component, or remove old values of CompressedName and DecompressedName. This may be done by first clearing the Files collection.

Example

ZipControl.IncludeFiles("c:\test\* | c:\readme") ZipControl.ExcludedFiles = "*.tmp" ZipControl.Compress()

Reset Method (Zip Component)

Resets the component.

Syntax

public void reset();

Remarks

Reset resets the state of the component. The Files collection will be cleared, all properties will be set to their default values, and any files open will be closed.

Scan Method (Zip Component)

Scans the compressed archive.

Syntax

public void scan();

Remarks

This method will scan the archive specified by ArchiveFile. The number of files and their names and sizes will be determined and written to the Files collection.

After scanning the archive, the values of DecompressedName may be changed if desired, and any number of files may be decompressed. The Extract method allows you to decompress files of your choice, and the ExtractAll method will decompress the entire archive.

Changing the values of the CompressedName field or the number of files in the Files collection will invalidate the scan. If either of these is changed and Extract or ExtractAll is then called; Scan will automatically be called again, and these values will be reset to their original values.

Calling this method will frequently generate a trappable error if the archive is corrupt. This is not guaranteed, however, as Scan only examines the headers.

Example

Dim i as Integer ZipControl.ArchiveFile = "c:\temp.zip" ZipControl.Scan() For i = 0 to ZipControl.Files(i).Count -1 Debug.Write("File name : ") Debug.Write(ZipControl.Files(i).DecompressedName) Debug.Write(" Size: ") Debug.WriteLine(ZipControl.Files(i).DecompressedSize) Next i

SetArchiveInputStream Method (Zip Component)

The stream to read the zip, tar, jar, or gzip archive from.

Syntax

public void setArchiveInputStream(java.io.InputStream archiveStream);

Remarks

This method should be set when the archive is to be read from a stream when Extract is called.

By default, and when this is set to null, the component will read from the file specified by ArchiveFile. However, when this is a valid stream, the data will be read from the stream.

SetArchiveOutputStream Method (Zip Component)

The stream to write the zip, tar, jar, or gzip archive to.

Syntax

public void setArchiveOutputStream(java.io.OutputStream archiveStream);

Remarks

This method should be set when the archive is to be written to a stream when Compress is called.

By default, and when this is set to null, the component will write to the file specified by ArchiveFile. However, when this is a valid stream, the data will be written to the stream.

Update Method (Zip Component)

Will update certain files in an archive.

Syntax

public void update(String filenames);

Remarks

When this method is called, the component will attempt to update files in the specified archive with the current files listed in the files collection. You may use the Filenames parameter to tell the component which files in the collection/archive must be updated.

Directories should end with a slash ("/"). If a directory is specified, all files and subdirectories in the specified directory will be affected.

A pipe character ("|") should be used to separate multiple file or directory names. Alternatively, the method may be invoked repeatedly.

BeginFile Event (Zip Component)

Fired before each file is processed.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void beginFile(ZipBeginFileEvent e) {}
  ...
}

public class ZipBeginFileEvent {
  public int index;

  public boolean skip;

}

Remarks

BeginFile is fired before each file is processed by the compressor or decompressor, as appropriate. Index contains the array index of the file about to be processed, and the CompressedName, DecompressedName, CompressedSize (decompression only), and DecompressedSize fields of the Files collection for this index contain more detailed information about the file about to be processed.

When extracting, an alternate location may be specified by trapping the event, and modifying DecompressedName and/or ExtractToPath. If DecompressedName is set to an empty string, the file will not be written to disk. If WriteToProgressEvent is true, the file will still be decompressed, and the data may be extracted through the Progress event.

This event may also be trapped while compressing. CompressedName and DecompressedName may be changed.

You may set the Skip parameter to true in order to skip the file completely while compressing or extracting.

EndFile Event (Zip Component)

Fired after each file is processed.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void endFile(ZipEndFileEvent e) {}
  ...
}

public class ZipEndFileEvent {
  public int index;

}

Remarks

EndFile is fired after each file is processed by the compressor or decompressor, as appropriate. Index contains the array index of the file processed, and the CompressedName, DecompressedName, CompressedSize, and DecompressedSize fields in the Files collection for this index contain more detailed information about the file processed.

Error Event (Zip Component)

Information about non-fatal errors.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void error(ZipErrorEvent e) {}
  ...
}

public class ZipErrorEvent {
  public String description;

  public int errorCode;

  public int index;

  public String filename;

  public boolean ignore;

}

Remarks

The Error event is fired when non-fatal errors occur during compression or decompression. Note that if this event is fired during decompression this may indicate that the archive is corrupt.

By default these errors will cause the component to fail with an exception. The exception may be overridden by setting Ignore to true. This will cause the error to be ignored, the file will be skipped if necessary, and the component will continue operation.

ErrorCode will correspond to one of the following errors:


1	Bad or missing CRC-32 checksum.
2	Failed to set creation date of a file.
111	Can't open file for read (skipping).

Description contains a textual description of the error. Index and Filename contain the array index (where appropriate) and filename of the file being processed at the time of the error.

Overwrite Event (Zip Component)

Fired whenever a file exists and may be overwritten.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void overwrite(ZipOverwriteEvent e) {}
  ...
}

public class ZipOverwriteEvent {
  public String filename;

  public boolean overwrite;

}

Remarks

Overwrite is fired when a file is about to be overwritten, and would overwrite an existing file. The event is fired during decompression.

Filename contains the full name of the file, specified with its pathname.

Overwrite specifies whether or not the file will be overwritten. For Zip, Jar, and Tar, this is equal by default to the value of the OverwriteFiles property. For Gzip, this value defaults to true.

Either of the parameters may be changed when the event is fired. Changing the value of Overwrite will override the default behavior of the component, and cause the file to be overwritten or not overwritten, depending on the value set. If Filename is changed, the value of Overwrite will be ignored, and the file will be written with the specified name. If a file of the new name also exists this file will be silently overwritten.

Password Event (Zip Component)

Fired when a file is encrypted, and the file's password is incorrect.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void password(ZipPasswordEvent e) {}
  ...
}

public class ZipPasswordEvent {
  public int index;

  public String password;

}

Remarks

This event is fired when the component attempts to uncompress an encrypted file and the decryption fails due to an invalid password. The file may be identified in the collection by the Index parameter.

Setting the Password parameter in this event will cause the component to attempt to decrypt and decompress the file again with the specified password.

If the Password parameter is an empty string when this event completes, an error will occur.

Progress Event (Zip Component)

Fired as progress is made.

Syntax

public class DefaultZipEventListener implements ZipEventListener {
  ...
  public void progress(ZipProgressEvent e) {}
  ...
}

public class ZipProgressEvent {
  public byte[] data;

  public String filename;

  public long bytesProcessed;

  public int percentProcessed;

}

Remarks

The Progress event is automatically fired as compression or decompression is performed. When WriteToProgressEvent is true, the output data is provided through the Data parameter, allowing for it to be streamed out.

Filename contains the name of the file being written. If no file is being written, Filename will contain an empty string, and the output data will be provided exclusively through this event.

BytesProcessed contains the total number of uncompressed bytes processed. PercentProcessed contains the percent of uncompressed bytes processed, corresponding roughly to the running time of the operation.

For Gzip extraction only, BytesProcessed and PercentProcessed will reflect the number of compressed bytes extracted, as it is generally impossible to predetermine the total uncompressed size.

If WriteToProgressEvent is false, Data will contain null.

ZIPFile Type

The Zip file in the archive.

Remarks

This type contains information about the Zip file that either exists in the archive or is being added to the archive.

Fields

Attributes
int

The attributes of the files to be compressed or decompressed. It will then be written to the archive during compression and to the file system during extraction.

If desired, you may change the value of Attributes before compressing or decompressing.

The property is a bitmask of flags, corresponding to the MS-DOS directory byte:


Readonly	1
Hidden	2
System	4
Directory	16
Archive	32

In the Java Edition, due to limitations of the JRE, the effect of this property is limited. When including files, only the Hidden and Readonly bits will be read from the file system, and during extraction only the Readonly attribute will be written.

Comment
String

Specifies a comment for the entry in the zip file. Before compression, set This field to include comments in this zip file. After an archive has been scanned, This field will contain any comments the zip file contains.

CompressedDate
long

The date and time of the entry, as stored within the archive.

FileCompressedDate contains the last modified date of the file, as stored within the archive (it does not generally correspond to when the file was compressed).

FileCompressedDate is returned in a platform-specific format. The Java,C++, and most other Editions will return the number of milliseconds since January 1, 1970, 00:00:00. This value may be passed directly to the java.util.Date constructor to create a java.util.Date object representing this date.

The .NET Edition will return the number of ticks, or 100-nanosecond intervals, since January 1, 0001, 00:00:00. This value may be passed directly to the System.DateTime constructor to create a System.DateTime object representing this date.

Reading the value of this property will return a meaningful value only after the archive has been successfully scanned or decompressed, and only if the values of ArchiveFile, Files collection, and CompressedName have not been changed since. If a meaningful value is not available this property will return a value of 0.

NOTE: This may be set accordingly when the InputStream field is set to a valid stream to input the data for the current file. If not set, the default, 0, is used. Otherwise the value is read from disk.

CompressedName
String

The file name of the current file, as stored inside of the archive. This may be the same as in DecompressedName, but is not required to be.

All paths are stored in the archive in standard (UNIX) format. Pathnames specified in the host operating system's format will be immediately converted.

This field should generally be set with a relative path or with no path at all. The exact interpretation of the path is left to the decompression software; generally, pathnames will be interpreted as relative to a base directory, and these subdirectories will be created as needed. Absolute pathnames (paths beginning with a / character) will not be interpreted correctly by the component, and may or may not be interpreted correctly by other decompression software.

Paths should be specified in standard (UNIX) format. They may also be specified in the format native to the host operating system, in which case they will be immediately converted.

Example

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.Files.Add(new ZIPFile()) ZipControl.Files[0].DecompressedName = "c:\test\ipworkszip\temp\test.txt" ZipControl.Files[0].CompressedName = "readme.txt" ZipControl.Compress()

CompressedSize
long (read-only)

The size of the compressed data, as compressed within the archive. Headers, footers, etc., are not included in the size.

Reading the value of this property will return a meaningful value only after the archive has been compressed, scanned, or decompressed, and only if the values of ArchiveFile, or Files have not been changed since. If a meaningful value is not available this property will return a value of -1.

CompressionLevel
int

The compression level to use for the file. This property specifies the level of compression to be used, between 0 and 6. Higher values will cause the component to compress better; lower values will cause the component to compress faster. A value of 0 will store the file without compression.

CRC
long (read-only)

The CRC value for the specified file found in the archive. This value is populated after compression or decompression.

DecompressedName
String

The name of the file in the archive, as stored on the file system, outside the archive.

When compressing files, This field should be specified with a path, if necessary, to allow the file to be found by the component. If the file cannot be found during compression, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, the field indicates where the file should be written. After the archive is scanned, the values of CompressedName and DecompressedName will be set to the exact filenames found in the archive. The value of DecompressedName may then be changed if desired.

If DecompressedName is set to an empty string before extraction, the file will not be written to disk at all. It will still be written to the Progress event if WriteToProgressEvent is set to true.

If DecompressedName is set to an empty string before compression, the file will be skipped, and not written to the archive.

A base path for decompression may be specified by setting the ExtractToPath property. If ExtractToPath is set to a non-empty string, the files will be decompressed to the directory specified in ExtractToPath. If the value of DecompressedName contains a pathname it will be regarded as relative to ExtractToPath.

Paths on the local file system should be specified in the format native to the host operating system. They may also be specified in standard (UNIX) format, in which case they will be immediately converted.

Example

ZipControl.ArchiveFile = "c:\test.tar" ZipControl.Scan() ZipControl.ExtractToPath = "c:\temp\" ZipControl.Files[1].DecompressedName = "test\temp.out" ZipControl.Extract(ZipControl.Files[1].CompressedName) Incorrect Example ZipControl.ExtractToPath = "c:\temp\" ZipControl.Files[1].DecompressedName = "c:\temp\test\temp.out" 'The file would be extracted to c:\temp\c:\temp\test\temp.out

DecompressedSize
long (read-only)

The size of the file, as decompressed outside the archive. If an archive is open for read (i.e. has been scanned or decompressed), this information will be read from the archive headers. If an archive is not open for read, the component will retrieve the information for the corresponding value of DecompressedName from the local file system.

A value of -1 will be returned in case of an I/O error.

EncryptionAlgorithm
int

The algorithm used to encrypt the specified file written to the archive.

Note that the file will only be encrypted if Password is set. By default the component will use standard zip encryption if Password is set, and will not encrypt data otherwise.

The component supports the use of AES with key lengths of 128, 192, or 256 bits. Note that even with the weakest (128-bit) keys AES is much more secure than standard Zip encryption.

If using AES encryption it is important to choose a good Password. For 128-bit keys it is recommended that your password be 32 characters long, and for 256-bit keys, 64 characters.

To set the EncryptionAlgorithm or Password fields for the entire archive, use the EncryptionAlgorithm or Password properties.

Property values:


eaDefault	0
eaAESWeak	1
eaAESStrong	2
etAESMaximum	3

Hash
String (read-only)

The computed hash for the specified File.

This field is populated with the hash value computed for the specified file after calling Compress. This field is only applicable if the FileHashAlgorithm configuration setting is set.

InputData
String

When This field is set, the component will read in the data from This field instead of reading from the file contained in the DecompressedName field.

InputDataB
byte []

When This field is set, the component will read in the data from This field instead of reading from the file contained in the DecompressedName field.

InputStream
java.io.InputStream

When this field is set to a valid stream, the component will read in the data from the stream as the current file instead of reading from the file contained in the DecompressedName field.

OutputStream
java.io.OutputStream

When this field is set to a valid stream, the component will extract the data to the stream rather than to the location specified by ExtractToPath.

NOTE: It is necessary to call Scan on the location specified by ArchiveFile before extracting in order to iterate through all of the members of Files and set each OutputStream field to a valid stream.

Password
String

This field specifies the case-sensitive password used to encrypt or decrypt the current file. If set to an empty string, no password is used.

For archives that have multiple files with the same password, you may use the Password property instead of the Password field of the Files collection. You may also use PasswordRequired field to see if a file requires a password after an archive has been scanned.

In this release, streaming out of encrypted archives is not supported. When compressing, WriteToProgressEvent must be set to false if Password is set.

Example (Compressing an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Password = "nsoftware" ZipControl.Compress()

PasswordRequired
boolean (read-only)

This field describes whether or not the current file has been encrypted or not and requires a password to decompress. It is populated after the archive has been scanned.

Constructors

public ZIPFile();

public ZIPFile( decompressedName);

public ZIPFile( compressedName,  decompressedName);

public ZIPFile( compressedName,  inputStream);

Config Settings (Zip Component)

The component accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

Zip Config Settings

AESGenerateUniqueKeys: Whether to generate unique keys for each file encrypted.

This setting controls the algorithm that generates AES cryptographic keys from the Password specified. For added security, a random salt value is generated, and a unique key will be generated for every unique combination of Password and salt.

If true, a unique salt value and key will be generated for each file encrypted. If false, a single salt value and key will be generated for all encrypted files in the archive.

If you are encrypting a lot of files, the value of this setting can have a substantial effect on both security and performance. By default, the component will set this to false.

CheckForFileLocks: If true, the component requests an exclusive lock during initialization.

If set to true, the component will request an exclusive lock during initialization to ensure there are no other processes locking a file. This is a temporary lock and is released before work is done. This is especially useful when another process has a partial lock on a file, for instance when Outlook is working with a .pst.

False by default.

CloseArchiveAfterCompress: Whether to close the archive after calling Compress.

This setting determines whether the archive is closed after calling Compress. When set to False the archive remains open and additional files can be added at any time. This allows files to be added to the archive incrementally as they become available. For instance: zip.Config("CloseArchiveAfterCompress=false"); //Add one file zip.Files.Add(new ZIPFile("..\\..\\files\\test.txt")); zip.Compress(); //Add another file zip.Files.Clear(); zip.Files.Add(new ZIPFile("..\\..\\files\\test2.txt")); zip.Compress(); //Ready to finish creating the archive zip.Config("CloseArchiveAfterCompress=true"); zip.Files.Clear(); zip.Compress(); //Must be called to finish archive creation As illustrated in the code above this setting must be set to True after all files are added to the archive and Compress must be called a final time to complete the archive creation.

The default value of this setting is True.

CloseStreamAfterCompress: If true, the component will close the output stream after compression.

This property is true by default. Therefore, by default, the output stream will be closed after compression is completed. In order to keep streams open after the compression completes, you must set this config to false.

CompressionMethod: Used to set the method of compression.

This is used to specify different compression methods. By default the component uses the Deflate compression method (a value of 0). Supported values are:


Value	Method
0	Deflate (default)
1	PPMd

EnableStreamingEncryption: Whether to allow streaming and encryption simultaneously.

If true, the component will allow encrypted files to be streamed out during compression; i.e., the component will allow you to compress with WriteToProgressEvent set to true or with SetArchiveOutputStream set to a valid stream and a Password has been set.

Use extreme caution when setting this option, as streamed and encrypted zip files may be unreadable by other zip software.

Encoding: Encoding to be used for filenames.

The encoding to be used for filenames, and for Zip files, the password. The file contents are treated as binary data, and so encoding does not apply to the contents. At present only supported for Zip and Jar.

Default - Zip: "" (use default encoding of current machine, if possible)

Default - Jar: "UTF-8"

Example - This would set encoding to Japanese Shift-JIS.

Zip1.Config("Encoding=SJIS");

ExcludedAttributes: Attributes of files to be excluded.

Files with attributes matching those specified will be excluded from compression or decompression. May be set to any combination of H (hidden), S (system), A (archive), and R (read-only). (Example: "HSR") Alternatively, may be set to a bitmask of the following flags: Readonly (1), Hidden (2), System (4), Directory (16), Archive (32).

For Java, when compressing, attributes other than "H" and "R" will be ignored (due to JRE limitations).

Default: "" (no excluded attributes)

ExtractFilesOnly: Whether to only extract the files contained within the archive.

If true, only the files contained within the ArchiveFile are extracted directly to the specified ExtractToPath. Folders contained within the ArchiveFile will not be created within the ExtractToPath. If an archive contains files with the same name, you can control whether or not they get overwritten by setting OverwriteFiles.

FileHashAlgorithm: The algorithm to use when computing the file hash.

This setting specifies the algorithm (if any) to use when computing the hash for files within the archive. If specified, when Compress is called the hash will be computed for each file within the archive and Hash will be populated with the computed hash value. Possible values are:

"" (Default - no hash is computed)
"SHA1"
"SHA224"
"SHA256"
"SHA284"
"MD5"

ForceZip64Format: Whether to explicitly compress a Zip64 format archive.

Setting this value to true will force the component to always create a Zip64 format archive when compressing. By default, this value is false and the component will detect whether or not compressing in Zip64 format is necessary.

MarkAsText: Whether to mark files as text files.

If true, the component will mark files as text within the zip archive. This may allow decompression software on other platforms to translate between character sets, etc.

If false (the default), files will be written as binary. To mark some files as text and others as binary, it is recommended that you trap the BeginFile event and set this property value as appropriate for each file.

OverwriteReadonlyFiles: Whether to overwrite readonly files.

If true, the component will overwrite readonly files when decompressing. If false (the default), the component will fire the Error event, instead, and will fail with an exception if the error is not trapped and explicitly ignored in the event.

PreserveModifiedTime: Whether or not to preserve the original modified time on extracted files.

Specifies whether or not the modified time of the extracted files use the current time or the original time of the file in the archive.

When set to True (default) the extracted files will have the same modified time as the original file.

When set to False the modified time on the extracted files will be set to the current time.

UseIBM437ASDefaultEncoding: Whether or not to use the IBM437 default encoding.

Specifies whether the default IBM437 or UTF-8 encoding should be used.

By default, this config is set to true.

VerifyPassword: Check whether the specified Password can decrypt the archive without extracting files.

If the password set in the Password property can successfully decrypt the archive, this config will return the string "True". Otherwise, it will return the string "False". No files are extracted when this config is referenced.

For example: Zip zip = new Zip(); zip.ArchiveFile = myArchive; zip.Password = myPassword; string verified = zip.Config("VerifyPassword"); // verified contains either "True" or "False"

WriteToProgressEvent: Whether or not to write data to the Progress Event.

If WriteToProgressEvent is set to true, then all data produced through invocations of Extract, ExtractAll, and Compress will be written to the Progress event as well as to disk. Applications may stream out the compressed or decompressed data by trapping this event and copying the data.

If WriteToProgressEvent is set to false, the data will not be streamed out, and the Data parameter of the Progress event will contain null.

Note that if streaming is enabled the zip files written will be slightly larger. Moreover, zip files produced with WriteToProgressEvent may be incompatible with certain older zip utilities.

By default, Password encryption is not allowed for archives created with WriteToProgressEvent set to true. You may set the EnableStreamingEncryption setting to allow this, but streamed and encrypted zip files may be incompatible with other utilities.

By default, this config is set to false.

Base Config Settings

BuildInfo: Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable: Tells the component whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.

LicenseInfo: Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

Product: The product the license is for.
Product Key: The key the license was generated from.
License Source: Where the license was found (e.g., RuntimeLicense, License File).
License Type: The type of license installed (e.g., Royalty Free, Single Server).
Last Valid Build: The last valid build number for which the license will work.

MaskSensitive: Whether sensitive data is masked in log messages.

In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to true to mask sensitive data. The default is true.

This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.

UseDaemonThreads: Whether threads created by the component are daemon threads.

If set to True (default), when the component creates a thread, the thread's Daemon property will be explicitly set to True. When set to False, the component will not set the Daemon property on the created thread. The default value is True.

UseInternalSecurityAPI: Tells the component whether or not to use the system security libraries or an internal implementation.

When set to false, the component will use the system security libraries by default to perform cryptographic functions where applicable.

Setting this setting to true tells the component to use the internal implementation instead of using the system security libraries.

This setting is set to false by default on all platforms.

Trappable Errors (Zip Component)

Errors

The following errors may be generated by the component. Note that frequently the error message will contain more specific information than what is listed here.

Note that some non-fatal errors may be trapped and explicitly ignored in the Error event. This will allow the component to continue operation even in case of error.

Zip Errors


	101 The zip archive is of an invalid or unsupported format.
	105 The password is missing or incorrect.
	106 Encryption is not supported when streaming is enabled.
	111 Can't open file for read.
	112 Can't open file for write.
	113 Can't create directory.
	114 The file is too large.
	115 Can't create empty archive.
	116 The archive must be scanned prior to attempting this operation.
	117 The array index is out of range.
	118 The maximum size of the archive has been exceeded.
	119 The archive must be specified, or streaming must be enabled.
	120 The component is busy.
	124 Must specify the compressed name.
	127 Bad CRC-32 checksum.
	128 Unable to set file date.
	133 File already exists in the archive.
	150 An I/O error has occurred (details follow).