net.siefkes.nlstego.util
Class InOutUtils

java.lang.Object
  net.siefkes.nlstego.util.InOutUtils

public final class InOutUtils
extends Object

A static class that provides utility constants and methods for I/O. No instances of this class can be created, only the static members should be used.

Version:

$Revision: 1.2 $, $Date: 2005/07/12 17:02:22 $, $Author: siefkes $

Author:

Christian Siefkes

Field Summary

static String	LINE_SEPARATOR The line separator on the current operating system ("\n" on Unix).
static int	STANDARD_BLOCK_SIZE The standard block size recommended for I/O.
static String	STANDARD_HTTP_CHARSET The standard character set defined by the HTTP standard.
static String	STANDARD_UNICODE_CHARSET The standard Unicode-compatible character set.

Method Summary

static byte[]	compress(byte[] data) Compresses data using GZip for compression.
static FileContent[]	listFileContents(String[] filePaths, boolean recurse) This method converts an array of file paths into an array of FileContent objects.
static Reader	openReader(FileContent content) Opens a reader on a FileContent object.
static byte	readExpectedByte(InputStream in) Reads a byte from an input stream, throwing an EOFException if the end of the stream has been reached.
static String	readToString(Reader reader) Reads the contents of a reader into a string.
static boolean	tryToClose(InputStream in) Convenience method for closing an input stream.
static boolean	tryToClose(OutputStream out) Convenience method for closing an output stream.
static boolean	tryToClose(Reader reader) Convenience method for closing a reader.
static boolean	tryToClose(Writer writer) Convenience method for closing a writer.
static byte[]	uncompress(byte[] compressedData) Uncompresses data using GZip.
static String	userDir() Returns the user's current working directory.
static String	userHome() Returns the user's home directory.

Methods inherited from class java.lang.Object

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

Field Detail

LINE_SEPARATOR

public static final String LINE_SEPARATOR

The line separator on the current operating system ("\n" on Unix).

STANDARD_BLOCK_SIZE

public static final int STANDARD_BLOCK_SIZE

The standard block size recommended for I/O.

See Also:

Constant Field Values

STANDARD_HTTP_CHARSET

public static final String STANDARD_HTTP_CHARSET

The standard character set defined by the HTTP standard.

See Also:

Constant Field Values

STANDARD_UNICODE_CHARSET

public static final String STANDARD_UNICODE_CHARSET

The standard Unicode-compatible character set.

See Also:

Constant Field Values

Method Detail

compress

public static byte[] compress(byte[] data)
                       throws IOException

Compresses data using GZip for compression.

Parameters:

data - the data to compress

Returns:

a byte array containing the compressed data

Throws:

IOException - if an I/O error occurs

listFileContents

public static FileContent[] listFileContents(String[] filePaths,
                                             boolean recurse)
                                      throws IOException

This method converts an array of file paths into an array of FileContent objects. It uses the Jakarta Commons Virtual File System (VFS) which allows accessing local files, URIs, ZIP entries and various other resources in a uniform way.

Parameters:

filePaths - the array of file paths

recurse - whether to recursively add the children of folders and other files containing nested entries

Returns:

an array of objects representing the contents of the resolved path names

Throws:

IOException - if an I/O error occurs, e.g. if one of the files does not exist

openReader

public static Reader openReader(FileContent content)
                         throws FileSystemException,
                                UnsupportedEncodingException

Opens a reader on a FileContent object. Uses the character set specified by FileContentInfo or the default character set of the current platform if no explicit charset is given.

Parameters:

content - the content to read

Returns:

a reader on the given object

Throws:

FileSystemException - if an error occurs while using the content object

UnsupportedEncodingException - if the specified charset is not available on the current platform

readToString

public static String readToString(Reader reader)
                           throws IOException

Reads the contents of a reader into a string. The reader is not closed by this method.

This method should be slightly more efficient than IOUtils.toString(java.io.Reader) since it uses an unsynchronized StringBuilder instead of a synchronized StringBuffer (hidden in a StringWriter).

Parameters:

reader - the reader to use

Returns:

the contents of the reader

Throws:

IOException - if an I/O error occurs

uncompress

public static byte[] uncompress(byte[] compressedData)
                         throws IOException

Uncompresses data using GZip.

Parameters:

compressedData - the data the uncompressed

Returns:

the uncompressed data

Throws:

IOException - if an I/O error occurs

readExpectedByte

public static byte readExpectedByte(InputStream in)
                             throws EOFException,
                                    IOException

Reads a byte from an input stream, throwing an EOFException if the end of the stream has been reached.

Parameters:

in - the stream to read from

Returns:

the read byte

Throws:

EOFException - if the end of the stream has been reached

IOException - if the end of the stream has been reached or if any other I/O error occurs

userDir

public static String userDir()

Returns the user's current working directory. This is just a shortcut for calling System.getProperty("user.dir").

Returns:

the current working directory

userHome

public static String userHome()

Returns the user's home directory. This is just a shortcut for calling System.getProperty("user.home").

Returns:

the home directory

tryToClose

public static boolean tryToClose(InputStream in)

Convenience method for closing an input stream. If the specified stream is null, this method does nothing. Any IOException thrown during closing is swallowed by this method.

Parameters:

in - the input stream to close (might be null)

Returns:

true if the stream was closed successfully, false otherwise (the stream was null or an exception was thrown during closing)

tryToClose

public static boolean tryToClose(OutputStream out)

Convenience method for closing an output stream. If the specified stream is null, this method does nothing. Any IOException thrown during closing is swallowed by this method.

Parameters:

out - the output stream to close (might be null)

Returns:

true if the stream was closed successfully, false otherwise (the stream was null or an exception was thrown during closing)

tryToClose

public static boolean tryToClose(Reader reader)

Convenience method for closing a reader. If the specified reader is null, this method does nothing. Any IOException thrown during closing is swallowed by this method.

Parameters:

reader - the reader to close (might be null)

Returns:

true if the reader was closed successfully, false otherwise (reader was null or an exception was thrown during closing)

tryToClose

public static boolean tryToClose(Writer writer)

Convenience method for closing a writer. If the specified writer is null, this method does nothing. Any IOException thrown during closing is swallowed by this method.

Parameters:

writer - the writer to close (might be null)

Returns:

true if the writer was closed successfully, false otherwise (writer was null or an exception was thrown during closing)