CkGzip Java Reference Documentation

CkGzip

Current Version: 9.5.0.97

GZip compression component.

Object Creation

CkGzip obj = new CkGzip();

Properties

AbortCurrent
boolean get_AbortCurrent();
void put_AbortCurrent(boolean newVal);
Introduced in version 9.5.0.58

When set to true, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to false when the next method is called. When the abort occurs, this property is reset to false. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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Comment
void get_Comment(CkString str);
String comment();
void put_Comment(String newVal);

Specifies an optional comment string that can be embedded within the .gz when any Compress* method is called.

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CompressionLevel
int get_CompressionLevel();
void put_CompressionLevel(int newVal);
Introduced in version 9.5.0.50

The compression level to be used when compressing. The default is 6, which is the typical value used for zip utility programs when compressing data. The compression level may range from 0 (no compression) to 9 (the most compression). The benefits of trying to increase compression may not be worth the added expense in compression time. In many cases (which is data dependent), the improvement in compression is minimal while the increase in computation time is significant.

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DebugLogFilePath
void get_DebugLogFilePath(CkString str);
String debugLogFilePath();
void put_DebugLogFilePath(String newVal);

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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ExtraData
void get_ExtraData(CkByteData byteData);
void put_ExtraData(CkByteData newVal);

Optional extra-data that can be included within a .gz when a Compress* method is called.

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Filename
void get_Filename(CkString str);
String filename();
void put_Filename(String newVal);

The filename that is embedded within the .gz during any Compress* method call. When extracting from a .gz using applications such as WinZip, this will be the filename that is created.

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HeartbeatMs
int get_HeartbeatMs();
void put_HeartbeatMs(int newVal);

The number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any method call prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

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LastErrorHtml
void get_LastErrorHtml(CkString str);
String lastErrorHtml();

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
void get_LastErrorText(CkString str);
String lastErrorText();

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
void get_LastErrorXml(CkString str);
String lastErrorXml();

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
boolean get_LastMethodSuccess();
void put_LastMethodSuccess(boolean newVal);

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = true and failure = false.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastModStr
void get_LastModStr(CkString str);
String lastModStr();
void put_LastModStr(String newVal);

The same as the LastMod property, but allows the date/time to be get/set in RFC822 string format.

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UseCurrentDate
boolean get_UseCurrentDate();
void put_UseCurrentDate(boolean newVal);

If set to true, the file produced by an Uncompress* method will use the current date/time for the last-modification date instead of the date/time found within the Gzip format.

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VerboseLogging
boolean get_VerboseLogging();
void put_VerboseLogging(boolean newVal);

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
void get_Version(CkString str);
String version();

Version of the component/library, such as "9.5.0.94"

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Methods

CompressBd
boolean CompressBd(CkBinData binDat);
Introduced in version 9.5.0.67

In-place gzip the contents of binDat.

Returns true for success, false for failure.

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CompressBdAsync (Android™) (Java)
CkTask CompressBdAsync(CkBinData binDat);
Introduced in version 9.5.0.67

Creates an asynchronous task to call the CompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressFile
boolean CompressFile(String inFilename, String destPath);

Compresses a file to create a GZip compressed file (.gz).

Returns true for success, false for failure.

More Information and Examples
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CompressFileAsync (Android™) (Java)
CkTask CompressFileAsync(String inFilename, String destPath);

Creates an asynchronous task to call the CompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressFile2
boolean CompressFile2(String inFilename, String embeddedFilename, String destPath);

Compresses a file to create a GZip compressed file (.gz). inFilename is the actual filename on disk. embeddedFilename is the filename to be embedded in the .gz such that when it is un-gzipped, this is the name of the file that will be created.

Returns true for success, false for failure.

More Information and Examples
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CompressFile2Async (Android™) (Java)
CkTask CompressFile2Async(String inFilename, String embeddedFilename, String destPath);

Creates an asynchronous task to call the CompressFile2 method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressFileToMem
boolean CompressFileToMem(String inFilename, CkByteData outData);

Gzip compresses a file to an in-memory image of a .gz file.

Note: There is a 4GB size limitation. The compressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns true for success, false for failure.

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CompressFileToMemAsync (Android™) (Java)
CkTask CompressFileToMemAsync(String inFilename);

Creates an asynchronous task to call the CompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressMemory
boolean CompressMemory(CkByteData inData, CkByteData outData);

Compresses in-memory data to an in-memory image of a .gz file.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns true for success, false for failure.

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CompressMemoryAsync (Android™) (Java)
CkTask CompressMemoryAsync(CkByteData inData);

Creates an asynchronous task to call the CompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressMemToFile
boolean CompressMemToFile(CkByteData inData, String destPath);

Gzip compresses and creates a .gz file from in-memory data.

Returns true for success, false for failure.

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CompressMemToFileAsync (Android™) (Java)
CkTask CompressMemToFileAsync(CkByteData inData, String destPath);

Creates an asynchronous task to call the CompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressString
boolean CompressString(String inStr, String destCharset, CkByteData outData);

Gzip compresses a string and writes the output to a byte array. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns true for success, false for failure.

More Information and Examples
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CompressStringAsync (Android™) (Java)
CkTask CompressStringAsync(String inStr, String destCharset);

Creates an asynchronous task to call the CompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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CompressStringENC
boolean CompressStringENC(String inStr, String charset, String encoding, CkString outStr);
String compressStringENC(String inStr, String charset, String encoding);

The same as CompressString, except the binary output is returned in encoded string form according to the encoding. The encoding can be any of the following: "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns true for success, false for failure.

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CompressStringToFile
boolean CompressStringToFile(String inStr, String destCharset, String destPath);

Gzip compresses a string and writes the output to a .gz compressed file. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns true for success, false for failure.

More Information and Examples
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CompressStringToFileAsync (Android™) (Java)
CkTask CompressStringToFileAsync(String inStr, String destCharset, String destPath);

Creates an asynchronous task to call the CompressStringToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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Decode
boolean Decode(String encodedStr, String encoding, CkByteData outData);

Decodes an encoded string and returns the original data. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns true for success, false for failure.

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DeflateStringENC
boolean DeflateStringENC(String inString, String charsetName, String outputEncoding, CkString outStr);
String deflateStringENC(String inString, String charsetName, String outputEncoding);

Provides the ability to use the zip/gzip's deflate algorithm directly to compress a string. Internal to this method, inString is first converted to the charset specified by charsetName. The data is then compressed using the deflate compression algorithm. The binary output is then encoded according to outputEncoding. Possible values for outputEncoding are "hex", "base64", "url", and "quoted-printable".

Note: The output of this method is compressed data with no Gzip file format. Use the Compress* methods to produce Gzip file format output.

Returns true for success, false for failure.

More Information and Examples
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Encode
boolean Encode(CkByteData byteData, String encoding, CkString outStr);
String encode(CkByteData byteData, String encoding);

Encodes binary data to a printable string. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns true for success, false for failure.

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ExamineFile
boolean ExamineFile(String inGzFilename);

Determines if the inGzFilename is a Gzip formatted file. Returns true if it is a Gzip formatted file, otherwise returns false.

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ExamineMemory
boolean ExamineMemory(CkByteData inGzData);

Determines if the in-memory bytes (inGzData) contain a Gzip formatted file. Returns true if it is Gzip format, otherwise returns false.

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GetDt
CkDateTime GetDt();

Gets the last-modification date/time to be embedded within the .gz.

Returns nil on failure

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InflateStringENC
boolean InflateStringENC(String inString, String convertFromCharset, String inputEncoding, CkString outStr);
String inflateStringENC(String inString, String convertFromCharset, String inputEncoding);

This the reverse of DeflateStringENC.

The input string is first decoded according to inputEncoding. (Possible values for inputEncoding are "hex", "base64", "url", and "quoted-printable".) The compressed data is then inflated, and the result is then converted from convertFromCharset (if necessary) to return a string.

Returns true for success, false for failure.

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LoadTaskCaller
boolean LoadTaskCaller(CkTask task);
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns true for success, false for failure.

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ReadFile
boolean ReadFile(String path, CkByteData outData);

Reads a binary file into memory and returns the byte array. Note: This method does not parse a Gzip, it is only a convenience method for reading a binary file into memory.

Returns true for success, false for failure.

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SetDt
boolean SetDt(CkDateTime dt);

Sets the last-modification date/time to be embedded within the .gz when a Compress* method is called. If not explicitly set, the current system date/time is used.

Returns true for success, false for failure.

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UncompressBd
boolean UncompressBd(CkBinData binDat);
Introduced in version 9.5.0.67

In-place ungzip the contents of binDat.

Returns true for success, false for failure.

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UncompressBdAsync (Android™) (Java)
CkTask UncompressBdAsync(CkBinData binDat);
Introduced in version 9.5.0.67

Creates an asynchronous task to call the UncompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressFile
boolean UncompressFile(String srcPath, String destPath);

Un-Gzips a .gz file. The output filename is specified by the 2nd argument and not by the filename embedded within the .gz.

Returns true for success, false for failure.

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UncompressFileAsync (Android™) (Java)
CkTask UncompressFileAsync(String srcPath, String destPath);

Creates an asynchronous task to call the UncompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressFileToMem
boolean UncompressFileToMem(String inFilename, CkByteData outData);

Un-Gzips a .gz file directly to memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns true for success, false for failure.

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UncompressFileToMemAsync (Android™) (Java)
CkTask UncompressFileToMemAsync(String inFilename);

Creates an asynchronous task to call the UncompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressFileToString
boolean UncompressFileToString(String gzFilename, String charset, CkString outStr);
String uncompressFileToString(String gzFilename, String charset);

Uncompresses a .gz file that contains a text file. The contents of the text file are returned as a string. The character encoding of the text file is specified by charset. Typical charsets are "iso-8859-1", "utf-8", "windows-1252", "shift_JIS", "big5", etc.

Returns true for success, false for failure.

More Information and Examples
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UncompressFileToStringAsync (Android™) (Java)
CkTask UncompressFileToStringAsync(String gzFilename, String charset);

Creates an asynchronous task to call the UncompressFileToString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressMemory
boolean UncompressMemory(CkByteData inData, CkByteData outData);

Un-Gzips from an in-memory image of a .gz file directly into memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns true for success, false for failure.

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UncompressMemoryAsync (Android™) (Java)
CkTask UncompressMemoryAsync(CkByteData inData);

Creates an asynchronous task to call the UncompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressMemToFile
boolean UncompressMemToFile(CkByteData inData, String destPath);

Un-Gzips from an in-memory image of a .gz file to a file.

Returns true for success, false for failure.

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UncompressMemToFileAsync (Android™) (Java)
CkTask UncompressMemToFileAsync(CkByteData inData, String destPath);

Creates an asynchronous task to call the UncompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressString
boolean UncompressString(CkByteData inData, String inCharset, CkString outStr);
String uncompressString(CkByteData inData, String inCharset);

The reverse of CompressString.

The bytes in inData are uncompressed, then converted from inCharset (if necessary) to return a string.

Returns true for success, false for failure.

More Information and Examples
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UncompressStringAsync (Android™) (Java)
CkTask UncompressStringAsync(CkByteData inData, String inCharset);

Creates an asynchronous task to call the UncompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UncompressStringENC
boolean UncompressStringENC(String inStr, String charset, String encoding, CkString outStr);
String uncompressStringENC(String inStr, String charset, String encoding);

The same as UncompressString, except the compressed data is provided in encoded string form based on the value of encoding. The encoding can be "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns true for success, false for failure.

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UnTarGz
boolean UnTarGz(String tgzFilename, String destDir, boolean bNoAbsolute);

Unpacks a .tar.gz file. The ungzip and untar occur in streaming mode. There are no temporary files and the memory footprint is constant (and small) while untarring. bNoAbsolute may be true or false. A value of true protects from untarring to absolute paths. (For example, imagine the trouble if the tar contains files with absolute paths beginning with /Windows/system32)

Returns true for success, false for failure.

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UnTarGzAsync (Android™) (Java)
CkTask UnTarGzAsync(String tgzFilename, String destDir, boolean bNoAbsolute);

Creates an asynchronous task to call the UnTarGz method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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WriteFile
boolean WriteFile(String path, CkByteData binaryData);

A convenience method for writing a binary byte array to a file.

Returns true for success, false for failure.

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XfdlToXml
boolean XfdlToXml(String xfldData, CkString outStr);
String xfdlToXml(String xfldData);

Converts base64-gzip .xfdl data to a decompressed XML string. The xfldData contains the base64 data. This method returns the decoded/decompressed XML string.

Returns true for success, false for failure.

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Events

Chilkat supports event callbacks in Java (including Android) starting in version 9.5.0.52. To implement an event callback, your application would define and implement a class that derives from CkBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkBaseProgress base class.

For example:

// Install an event callback handler to get progress events.
MyBaseProgress gzipProgress = new MyBaseProgress();
http.put_EventCallbackObject(gzipProgress);

MyBaseProgress example:

import com.chilkatsoft.CkBaseProgress;
import com.chilkatsoft.CkTask;

public class MyBaseProgress extends CkBaseProgress 
{	
  public boolean AbortCheck()
  {
    System.out.println("AbortCheck");
    // Return true to abort, false to allow the method to continue.
    return false;
  }
  	
  // pctDone is a value from 0 to 100
  // (it is actually value from 0 to the PercentDoneScale property setting)
  public boolean PercentDone(int pctDone)
  {
    System.out.println(pctDone);
    // Return true to abort, false to allow the method to continue.
    // Note: A PercentDone event is the equivalent of an AbortCheck.  
    // When PercentDone events are frequently firing, AbortCheck events are suppressed.
    // AbortCheck events will fire when the time between PercentDone events is longer 
    // than the HeartbeatMs property setting.
    return false;
  }
  
  public void ProgressInfo(String name, String value)
  {
    System.out.println(name + ": " + value);
  }
  
  public void TaskCompleted(CkTask task)
  {
     System.out.println("task completed!");
  }
  
}
AbortCheck
public boolean AbortCheck();

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200. Return true to abort; return false to continue (not abort)

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PercentDone
public boolean PercentDone(int pctDone);

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

Return true to abort; return false to continue (not abort)

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ProgressInfo
public void ProgressInfo(String name, String value);

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

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TaskCompleted
public void TaskCompleted(CkTask task);

Called in the background thread when an asynchronous task completes.

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