com.cloudhopper.commons.util

Class CompressionUtil

java.lang.Object

com.cloudhopper.commons.util.CompressionUtil

public class CompressionUtil
extends Object

Utility methods for compressing and uncompressing a file.

Author:

joelauer (twitter: @jjlauer or http://twitter.com/jjlauer)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CompressionUtil.Algorithm Enumeration of all supported compression algorithms by this utility.

Constructor Summary

Constructors

Constructor and Description
CompressionUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static File	compress(File sourceFile, File targetDir, String algorithm, boolean deleteSourceFileAfterCompressed) Compresses the source file using a variety of supported compression algorithms.
static File	compress(File sourceFile, String algorithm, boolean deleteSourceFileAfterCompressed) Compresses the source file using a variety of supported compression algorithms.
static boolean	isAlgorithmSupported(String algorithm) Checks if the compression algorithm is supported by this utility class.
static boolean	isFileExtensionSupported(String fileExt) Checks if the file extension such as "gz" or "zip" is supported by this utility class.
static File	uncompress(File sourceFile, boolean deleteSourceFileAfterUncompressed) Uncompresses the source file using a variety of supported compression algorithms.
static File	uncompress(File sourceFile, File targetDir, boolean deleteSourceFileAfterUncompressed) Uncompresses the source file using a variety of supported compression algorithms.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CompressionUtil

public CompressionUtil()

Method Detail

isAlgorithmSupported

public static boolean isAlgorithmSupported(String algorithm)

Checks if the compression algorithm is supported by this utility class. For example, "gzip" would return true while "unknown" would return false.

Parameters:

algorithm - The compression algorithm such as "gzip" or "zip"

Returns:

True if the algorithm is supported, otherwise false.

isFileExtensionSupported

public static boolean isFileExtensionSupported(String fileExt)

Checks if the file extension such as "gz" or "zip" is supported by this utility class. A file extension is supported if a compression algorithm exists.

Parameters:

fileExt - The file extension to check such as "gz" or "zip"

Returns:

True if the file extension is supported, otherwise false.

compress

public static File compress(File sourceFile,
            String algorithm,
            boolean deleteSourceFileAfterCompressed)
                     throws FileAlreadyExistsException,
                            IOException

Compresses the source file using a variety of supported compression algorithms. This method will create a target file in the same directory as the source file and will append a file extension matching the compression algorithm used. For example, using "gzip" will mean a source file of "app.log" would be compressed to "app.log.gz".

Parameters:

sourceFile - The uncompressed file

algorithm - The compression algorithm to use

deleteSourceFileAfterCompressed - Delete the original source file only if the compression was successful.

Returns:

The compressed file

Throws:

FileAlreadyExistsException - Thrown if the target file already exists and an overwrite is not permitted. This exception is a subclass of IOException, so its safe to only catch an IOException if no specific action is required for this case.

IOException - Thrown if an error occurs while attempting to compress the source file.

compress

public static File compress(File sourceFile,
            File targetDir,
            String algorithm,
            boolean deleteSourceFileAfterCompressed)
                     throws FileAlreadyExistsException,
                            IOException

Compresses the source file using a variety of supported compression algorithms. This method will create a destination file in the destination directory and will append a file extension matching the compression algorithm used. For example, using "gzip" will mean a source file of "app.log" would be compressed to "app.log.gz" and placed in the destination directory.

Parameters:

sourceFile - The uncompressed file

targetDir - The target directory or null if same directory as sourceFile

algorithm - The compression algorithm to use

deleteSourceFileAfterCompressed - Delete the original source file only if the compression was successful.

Returns:

The compressed file

Throws:

FileAlreadyExistsException - Thrown if the target file already exists and an overwrite is not permitted. This exception is a subclass of IOException, so its safe to only catch an IOException if no specific action is required for this case.

IOException - Thrown if an error occurs while attempting to compress the source file.

uncompress

public static File uncompress(File sourceFile,
              boolean deleteSourceFileAfterUncompressed)
                       throws FileAlreadyExistsException,
                              IOException

Uncompresses the source file using a variety of supported compression algorithms. This method will create a file in the same directory as the source file by stripping the compression algorithm's file extension from the source filename. For example, using "gzip" will mean a source file of "app.log.gz" would be uncompressed to "app.log".

Parameters:

sourceFile - The compressed file

deleteSourceFileAfterUncompressed - Delete the original source file only if the uncompression was successful.

Returns:

The uncompressed file

Throws:

FileAlreadyExistsException - Thrown if the target file already exists and an overwrite is not permitted. This exception is a subclass of IOException, so its safe to only catch an IOException if no specific action is required for this case.

IOException - Thrown if an error occurs while attempting to uncompress the source file.

uncompress

public static File uncompress(File sourceFile,
              File targetDir,
              boolean deleteSourceFileAfterUncompressed)
                       throws FileAlreadyExistsException,
                              IOException

Uncompresses the source file using a variety of supported compression algorithms. This method will create a file in the target directory by stripping the compression algorithm's file extension from the source filename. For example, using "gzip" will mean a source file of "app.log.gz" would be uncompressed to "app.log" and placed in the target directory.

Parameters:

sourceFile - The compressed file

targetDir - The target directory or null to uncompress in same directory as source file

deleteSourceFileAfterUncompressed - Delete the original source file only if the uncompression was successful.

Returns:

The uncompressed file

Throws:

FileAlreadyExistsException - Thrown if the target file already exists and an overwrite is not permitted. This exception is a subclass of IOException, so its safe to only catch an IOException if no specific action is required for this case.

IOException - Thrown if an error occurs while attempting to uncompress the source file.