# ZCompress Class

The ZCompress class implements an LZC compressor and decompressor. It is compatible with the UNIX compress utility.

## Syntax

```text
ipworkszip.ZCompress
```

## Remarks

The LZC file format is used only to archive a single file. Accordingly, the operation of the class is simpler than that of the other classes.

To compress with the class, set [ArchiveFile](#archivefile-property-zcompress-class) to the name of the LZC compressed file to be created, and [FileDecompressedName](#filedecompressedname-property-zcompress-class) to the name of the file to be compressed. Finally, invoke [Compress](#compress-method-zcompress-class). To extract the file, first set [ArchiveFile](#archivefile-property-zcompress-class). [FileDecompressedName](#filedecompressedname-property-zcompress-class) may then be set; if not, it will automatically be set based on the [ArchiveFile](#archivefile-property-zcompress-class) name. Finally, invoke the [Extract](#extract-method-zcompress-class) method.

**Example (Creating an LZC File)**

```text
ZipControl.ArchiveFile = "c:\test.Z"
ZipControl.FileDecompressedName = "c:\test.txt"
ZipControl.Compress()
```

 **Example (Extracting from an LZC File)**

```text
ZipControl.ArchiveFile = "c:\test.Z"
ZipControl.FileDecompressedName = "c:\test.txt"
ZipControl.Extract()
```

## Property List

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

|  |  |
| --- | --- |
| [ArchiveFile](#archivefile-property-zcompress-class) | The name of the zip, gzip, tar, or jar archive. |
| [FileDecompressedName](#filedecompressedname-property-zcompress-class) | File name to decompress to, or compress from. |
| [FileInputData](#fileinputdata-property-zcompress-class) | The data of the file to be compressed. |
| [ZCompressData](#zcompressdata-property-zcompress-class) | (Decompression only) The LZC compressed file contents as a byte array. |

## Method List

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

|  |  |
| --- | --- |
| [Abort](#abort-method-zcompress-class) | Aborts the current operation. |
| [Compress](#compress-method-zcompress-class) | Creates the compressed archive. |
| [Config](#config-method-zcompress-class) | Sets or retrieves a configuration setting. |
| [Extract](#extract-method-zcompress-class) | Extracts the compressed file from the archive. |
| [Reset](#reset-method-zcompress-class) | Resets the class. |
| [SetArchiveInputStream](#setarchiveinputstream-method-zcompress-class) | The stream to read the zip, tar, jar, or gzip archive from. |
| [SetArchiveOutputStream](#setarchiveoutputstream-method-zcompress-class) | The stream to write the zip, tar, jar, or gzip archive to. |
| [SetFileInputStream](#setfileinputstream-method-zcompress-class) | The input stream to read the decompressed data from. |

## 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.*

|  |  |
| --- | --- |
| [BeginFile](#beginfile-event-zcompress-class) | Fired before a file is processed. |
| [EndFile](#endfile-event-zcompress-class) | Fired after a file is processed. |
| [Error](#error-event-zcompress-class) | Information about non-fatal errors. |
| [Overwrite](#overwrite-event-zcompress-class) | Fired whenever a file exists and may be overwritten. |
| [Progress](#progress-event-zcompress-class) | Fired as progress is made. |

## Config Settings

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

|  |  |
| --- | --- |
| [CloseStreamAfterCompress](#CloseStreamAfterCompress) | If true, the class will close the output stream after compression. |
| [WriteToProgressEvent](#WriteToProgressEvent) | Whether or not to write data to the Progress Event. |
| [BuildInfo](#BuildInfo) | Information about the product's build. |
| [GUIAvailable](#GUIAvailable) | Whether or not a message loop is available for processing events. |
| [LicenseInfo](#LicenseInfo) | Information about the current license. |
| [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. |
| [UseDaemonThreads](#UseDaemonThreads) | Whether threads created by the class are daemon threads. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |
| [UseVirtualThreads](#UseVirtualThreads) | Whether threads created by the class use virtual threads instead of platform threads. |

# ArchiveFile Property ([ZCompress](#zcompress-class) Class)

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

## Syntax

```text
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](#extract-method-zcompress-class), 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](#compress-method-zcompress-class) is called, the file named by ArchiveFile will be written; if a file of this name already exists the [Overwrite](#overwrite-event-zcompress-class) 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](#progress-event-zcompress-class) 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 class.

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

**Example (Creating an Archive)**

```text
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 ("").

# FileDecompressedName Property ([ZCompress](#zcompress-class) Class)

File name to decompress to, or compress from.

## Syntax

```text
public String getFileDecompressedName();
public void setFileDecompressedName(String fileDecompressedName);
```

## Default Value

""

## Remarks

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

When compressing a file and [SetFileInputStream](#setfileinputstream-method-zcompress-class) has not been called with a valid input stream, this property should be specified with a path, if necessary, to allow the file to be found by the class. If the file cannot be found when [Compress](#compress-method-zcompress-class) is called, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, this property may be set prior to calling [Extract](#extract-method-zcompress-class). If this property is set to the empty string when [Extract](#extract-method-zcompress-class) is called, [Extract](#extract-method-zcompress-class) will automatically set this property to an appropriate value.

 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.

# FileInputData Property ([ZCompress](#zcompress-class) Class)

The data of the file to be compressed.

## Syntax

```text
public byte[] getFileInputData();
public void setFileInputData(byte[] fileInputData);
```

## Default Value

""

## Remarks

When this property is set, the class will read in the data from this property instead of reading from the file contained in the [FileDecompressedName](#filedecompressedname-property-zcompress-class) property.

This property is not available at design time.

# ZCompressData Property ([ZCompress](#zcompress-class) Class)

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

## Syntax

```text
public void setZCompressData(byte[] ZCompressData);
```

## Default Value

""

## Remarks

Normally you should set [ArchiveFile](#archivefile-property-zcompress-class) before invoking [Extract](#extract-method-zcompress-class). If you prefer to read the LZC compressed file from memory you may set ZCompressData instead. ZCompressData should be set to the entire contents of the LZC compressed 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](#WriteToProgressEvent) to true, and you should set the value of [FileDecompressedName](#filedecompressedname-property-zcompress-class) to an empty string. Then, when you invoke [Extract](#extract-method-zcompress-class) the data will be provided in the [Progress](#progress-event-zcompress-class) event.

This property is write-only. Note that modifying a LZC compressed file stored in ZCompressData is not supported.

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

# Abort Method ([ZCompress](#zcompress-class) Class)

Aborts the current operation.

## Syntax

```text
public void abort();
```

## Remarks

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

# Compress Method ([ZCompress](#zcompress-class) Class)

Creates the compressed archive.

## Syntax

```text
public void compress();
```

## Remarks

Invoking Compress creates the archive specified by [ArchiveFile](#archivefile-property-zcompress-class). When the method is called, the file specified by [FileDecompressedName](#filedecompressedname-property-zcompress-class) will be opened, and the file specified by [ArchiveFile](#archivefile-property-zcompress-class) will contain the compressed output.

# Config Method ([ZCompress](#zcompress-class) Class)

Sets or retrieves a configuration setting.

## Syntax

```text
public String config(String configurationString);
```

## Remarks

Config is a generic method available in every class. It is used to set and retrieve [configuration settings](#config-settings-zcompress-class) 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](#config-settings-zcompress-class), you must call *Config("PROPERTY")*. The value will be returned as a string.

# Extract Method ([ZCompress](#zcompress-class) Class)

Extracts the compressed file from the archive.

## Syntax

```text
public void extract();
```

## Remarks

Invoking Extract decompresses the archive specified by [ArchiveFile](#archivefile-property-zcompress-class). The compressed file will be extracted, and written to disk.

If [FileDecompressedName](#filedecompressedname-property-zcompress-class) is set to a nonempty string the file will be written there. Otherwise the class will automatically set [FileDecompressedName](#filedecompressedname-property-zcompress-class) to an appropriate value:

If [FileDecompressedName](#filedecompressedname-property-zcompress-class) is empty and [ArchiveFile](#archivefile-property-zcompress-class) ends in ".Z", this filename, less the ".Z" extension will be used. Otherwise the extension ".uncompressed" will be appended to the file name.

# Reset Method ([ZCompress](#zcompress-class) Class)

Resets the class.

## Syntax

```text
public void reset();
```

## Remarks

Reset resets the state of the class. All properties will be set to their default values, and any files open will be closed.

# SetArchiveInputStream Method ([ZCompress](#zcompress-class) Class)

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

## Syntax

```text
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](#extract-method-zcompress-class) is called.

By default, and when this is set to null, the class will read from the file specified by [ArchiveFile](#archivefile-property-zcompress-class). However, when this is a valid stream, the data will be read from the stream.

# SetArchiveOutputStream Method ([ZCompress](#zcompress-class) Class)

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

## Syntax

```text
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](#compress-method-zcompress-class) is called.

By default, and when this is set to null, the class will write to the file specified by [ArchiveFile](#archivefile-property-zcompress-class). However, when this is a valid stream, the data will be written to the stream.

# SetFileInputStream Method ([ZCompress](#zcompress-class) Class)

The input stream to read the decompressed data from.

## Syntax

```text
public void setFileInputStream(java.io.InputStream archiveStream);
```

## Remarks

When this method is set to a valid stream, the class will read in the data from the stream as the current file instead of reading from the file contained in the [FileDecompressedName](#filedecompressedname-property-zcompress-class) property.

# BeginFile Event ([ZCompress](#zcompress-class) Class)

Fired before a file is processed.

## Syntax

```text
public class DefaultZCompressEventListener implements ZCompressEventListener {
  ...
  public void beginFile(ZCompressBeginFileEvent e) {}
  ...
}

public class ZCompressBeginFileEvent {
  public int index;
  public boolean skip; //read-write
}
```

## Remarks

BeginFile is fired before compression or decompression begins. *Index* will contain 0.

You may use the *Skip* parameter to tell the component to skip the file when compressing or decompressing.

# EndFile Event ([ZCompress](#zcompress-class) Class)

Fired after a file is processed.

## Syntax

```text
public class DefaultZCompressEventListener implements ZCompressEventListener {
  ...
  public void endFile(ZCompressEndFileEvent e) {}
  ...
}

public class ZCompressEndFileEvent {
  public int index;
}
```

## Remarks

EndFile is fired when compression or decompression finishes. *Index* will contain 0.

# Error Event ([ZCompress](#zcompress-class) Class)

Information about non-fatal errors.

## Syntax

```text
public class DefaultZCompressEventListener implements ZCompressEventListener {
  ...
  public void error(ZCompressErrorEvent e) {}
  ...
}

public class ZCompressErrorEvent {
  public String description;
  public int errorCode;
  public int index;
  public String fileName;
  public boolean ignore; //read-write
}
```

## 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 class 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 ([ZCompress](#zcompress-class) Class)

Fired whenever a file exists and may be overwritten.

## Syntax

```text
public class DefaultZCompressEventListener implements ZCompressEventListener {
  ...
  public void overwrite(ZCompressOverwriteEvent e) {}
  ...
}

public class ZCompressOverwriteEvent {
  public String fileName; //read-write
  public boolean overwrite; //read-write
}
```

## 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 class, 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.

# Progress Event ([ZCompress](#zcompress-class) Class)

Fired as progress is made.

## Syntax

```text
public class DefaultZCompressEventListener implements ZCompressEventListener {
  ...
  public void progress(ZCompressProgressEvent e) {}
  ...
}

public class ZCompressProgressEvent {
  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](#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](#WriteToProgressEvent) is false, *Data* will contain null.

# Config Settings ([ZCompress](#zcompress-class) Class)

 The class 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 class, access to these *internal properties* is provided through the [Config](#config-method-zcompress-class) method.

### ZCompress Config Settings

**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.

**WriteToProgressEvent**: Whether or not to write data to the Progress Event.If [WriteToProgressEvent](#WriteToProgressEvent) is set to true, then all data produced through invocations of [Extract](#extract-method-zcompress-class), ExtractAll, and [Compress](#compress-method-zcompress-class) will be written to the [Progress](#progress-event-zcompress-class) 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](#WriteToProgressEvent) is set to false, the data will not be streamed out, and the *Data* parameter of the [Progress](#progress-event-zcompress-class) event will contain null.

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**: 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 class 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](#GUIAvailable) to *false* will ensure that the class 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 class 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.

**MaskSensitiveData**: 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*.

**UseDaemonThreads**: Whether threads created by the class are daemon threads.If set to True (default), when the class creates a thread, the thread's Daemon property will be explicitly set to True. When set to False, the class will not set the Daemon property on the created thread. The default value is True.

**UseInternalSecurityAPI**: Whether or not to use the system security libraries or an internal implementation. When set to *false*, the class will use the system security libraries by default to perform cryptographic functions where applicable.

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

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

**UseVirtualThreads**: Whether threads created by the class use virtual threads instead of platform threads.If set to *true*, when the class creates a thread, it will be created as a virtual thread instead of a platform thread. Virtual threads are lightweight threads managed by the JVM that are multiplexed onto a small pool of carrier threads, significantly reducing memory usage and platform thread count under high-concurrency workloads. Requires Java 24 or later. The default value is *false*.

# Trappable Errors ([ZCompress](#zcompress-class) Class)

 **Errors**

The following errors may be generated by the class. 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](#error-event-zcompress-class) event. This will allow the class to continue operation even in case of error.

### ZCompress Errors

|  |  |
| --- | --- |
| 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). |