ariba.util.core
Class IOUtil

java.lang.Object
  ariba.util.core.IOUtil

public final class IOUtil
extends Object

Input/Output Utilities. These are helper functions for dealing with i/o.

Nested Class Summary

static class

IOUtil.BufferHolder Holds a byte buffer for use in this class while copying bytes around.

Field Summary

static int

DefaultInternalBufferSize When internal buffers are used in buffered I/O, the size is specified by this value.

Method Summary

static BufferedInputStream	bufferedInputStream(File file) Opens a binary file on top of a buffered layer.
static BufferedOutputStream	bufferedOutputStream(File file) Opens a binary file on top of a buffered layer.
static BufferedOutputStream	bufferedOutputStream(File file, boolean append) Opens a binary file on top of a buffered layer.
static BufferedReader	bufferedReader(File file, String encoding) Opens a text file on top of a buffered layer.
static BufferedReader	bufferedReader(InputStream i, String encoding) Opens a text stream over a binary one on top of a buffered layer.
static BufferedWriter	bufferedWriter(OutputStream o, String encoding) Open a writer with the specified encoding
static byte[]	bytesFromURL(URL url) Read the contents of a URL as a byte array .
static void	close(InputStream in) Helper method to close an input stream without exceptions in a null safe manner.
static void	close(OutputStream out) Helper method to close an output stream without exceptions in a null safe manner.
static void	close(Reader in) Helper method to close a Reader without exceptions in a null safe manner.
static void	close(Writer out) Helper method to close a Writer without exceptions in a null safe manner.
static boolean	copyDirectory(File source, File target) Copy recursively a directory Use this with caution.
static boolean	copyDirectory(File source, File target, boolean recursive, boolean createTarget) Copy recursively a directory Use this with caution.
static boolean	copyFile(File sourceFile, File targetFile) Copy the contents of a file to another file.
static boolean	copyFile(File sourceFile, File targetFile, byte[] buffer) Copy the contents of a file to another file.
static boolean	copyFile(File sourceFile, File targetFile, char[] buffer) Deprecated. use copyFile(File, File, byte[])
static boolean	copyFileIfNewer(File sourceFile, File targetFile) Copy a file if the source is newer than the target
static void	copyUrlToFile(String sourceURLString, File targetFile) Copy a URL (String format) to File.
static boolean	deleteDirectory(File dir) Delete a directory and its subdirectories.
static String	getDefaultSystemEncoding() Return the System Wide default encoding.
static int	getInternalBufferHolderRecursionDepth() Returns the recursion depth of the internal per-thread BufferHolder.
static boolean	grep(File file, String regex) Returns true if the file contains a string matching regex and false otherwise.
static boolean	grep(File file, String regex, Charset charset) Returns true if the file contains a string matching regex and false otherwise.
static boolean	grep(Reader reader, String regex) Greps the supplied reader character stream for regex returning true the pattern is found in the character stream and false otherwise.
static boolean	inputStreamToOutputStream(InputStream input, OutputStream output) Copies all data from an InputStream to an OutputStream.
static boolean	inputStreamToOutputStream(InputStream input, OutputStream output, byte[] buffer, boolean flush) Copies all data from an InputStream to an OutputStream.
static int	inputStreamToOutputStream(InputStream input, OutputStream output, byte[] buffer, boolean flush, int bytesToCopy) Deprecated. Use spool(java.io.InputStream, java.io.OutputStream, byte[], boolean, long) instead.
static byte[]	makeByteBuffer() Returns a new byte array buffer of size DefaultInternalBufferSize.
static PrintWriter	printWriter(File file, String encoding) Opens a text file with a reasonable stream interface on top of a buffered layer.
static PrintWriter	printWriter(OutputStream o, String encoding) Open a text stream over a binary one on top of a buffered layer.
static PrintWriter	printWriter(OutputStream o, String encoding, boolean autoFlush) Open a text stream over a binary one on top of a buffered layer.
static boolean	readerToWriter(Reader reader, Writer writer) Copy Reader to Writer.
static boolean	readerToWriter(Reader reader, Writer writer, char[] buffer) Copy Reader to Writer.
static String	readFirstLine(File file) Reads the first line from file assuming UTF-8.
static String	readFirstLine(File file, Charset charset) Reads and returns the first line from file using the specified charset to convert the bytes from the file into characters.
static String	readLine(InputStream in) Read a line from an InputStream.
static String	readLine(InputStream in, char[] lineBuffer) Read a line from an InputStream.
static void	searchReplace(File input, File output, String regexToFind, String toReplace) Searches and replaces input replacing regexToFind with toReplace writing to output.
static void	searchReplace(File input, File output, String regexToFind, String toReplace, Charset charset) Searches and replaces input replacing regexToFind with toReplace writing to output.
static void	searchReplace(File input, Writer writer, String regexToFind, String toReplace) Searches and replaces input replacing regexToFind with toReplace writing to writer.
static void	searchReplace(File input, Writer writer, String regexToFind, String toReplace, Charset charset) Searches and replaces file replacing regexToFind with toReplace writing to writer.
static void	searchReplace(Reader reader, Writer writer, String regexToFind, String toReplace) Searches the reader character stream and replaces every occurrence of regexToFind with the replacement string toReplace.
static int	spool(InputStream input, byte[] buffer) Copies up to buffer.length bytes from input to buffer.
static long	spool(InputStream input, OutputStream output) Copies all the bytes from input to output.
static long	spool(InputStream input, OutputStream output, byte[] buffer, boolean flushOutput, long length) Copies up to length bytes from input to output using the supplied buffer.
static long	spool(InputStream input, OutputStream output, byte[] buffer, long length) Copies up to length bytes from input to output using the supplied buffer.
static long	spool(InputStream input, OutputStream output, long length) Copies up to length bytes from input to output.
static String	stringFromURL(URL url, String encoding) Read the contents of a URL as a string.
static void	writeToFile(File file, Object object, boolean append) Writes object to file assuming UTF-8.
static void	writeToFile(File file, Object object, boolean append, Charset charset) Writes object to file using the specified charset.

Methods inherited from class java.lang.Object

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

Field Detail

DefaultInternalBufferSize

public static final int DefaultInternalBufferSize

When internal buffers are used in buffered I/O, the size is specified by this value.

See Also:

Constant Field Values

Method Detail

getInternalBufferHolderRecursionDepth

public static int getInternalBufferHolderRecursionDepth()

Returns the recursion depth of the internal per-thread BufferHolder.

Returns:

the per-thread BufferHolder recursion depth

makeByteBuffer

public static byte[] makeByteBuffer()

Returns a new byte array buffer of size DefaultInternalBufferSize. This method is used by this class for internal buffer allocation.

printWriter

public static PrintWriter printWriter(File file,
                                      String encoding)
                               throws IOException

Opens a text file with a reasonable stream interface on top of a buffered layer.

Parameters:

file - the file to open

encoding - the encoding to use

Returns:

a buffered PrintWriter wrapped around the file

Throws:

IOException - if there was an error opening the file

printWriter

public static PrintWriter printWriter(OutputStream o,
                                      String encoding)
                               throws UnsupportedEncodingException

Open a text stream over a binary one on top of a buffered layer.

Throws:

UnsupportedEncodingException

printWriter

public static PrintWriter printWriter(OutputStream o,
                                      String encoding,
                                      boolean autoFlush)
                               throws UnsupportedEncodingException

Open a text stream over a binary one on top of a buffered layer.

Throws:

UnsupportedEncodingException

bufferedWriter

public static BufferedWriter bufferedWriter(OutputStream o,
                                            String encoding)
                                     throws UnsupportedEncodingException

Open a writer with the specified encoding

Throws:

UnsupportedEncodingException

bufferedReader

public static BufferedReader bufferedReader(File file,
                                            String encoding)
                                     throws IOException

Opens a text file on top of a buffered layer.

Parameters:

file - the File to opened

encoding - the encoding to use

Returns:

a BufferedReader around the file

Throws:

IOException - if there was an error opening the file

bufferedReader

public static BufferedReader bufferedReader(InputStream i,
                                            String encoding)
                                     throws UnsupportedEncodingException

Opens a text stream over a binary one on top of a buffered layer.

Throws:

UnsupportedEncodingException

bufferedInputStream

public static BufferedInputStream bufferedInputStream(File file)
                                               throws IOException

Opens a binary file on top of a buffered layer.

Parameters:

file - the file to open

Returns:

a BufferedInputStream wrapping the file

Throws:

IOException - if there was an error opening the file

bufferedOutputStream

public static BufferedOutputStream bufferedOutputStream(File file)
                                                 throws IOException

Opens a binary file on top of a buffered layer.

Parameters:

file - the file to open

Returns:

a BufferedOutputStream wrapping the file

Throws:

IOException - if there was an error opening the file

bufferedOutputStream

public static BufferedOutputStream bufferedOutputStream(File file,
                                                        boolean append)
                                                 throws IOException

Opens a binary file on top of a buffered layer.

Parameters:

file - the file to open

append - true to append to the file, false otherwise.

Returns:

a BufferedOutputStream wrapping the file

Throws:

IOException - if there was an error opening the file

readLine

public static String readLine(InputStream in)
                       throws IOException

Read a line from an InputStream.

Parameters:

in - the stream to read from

Returns:

the line read, without the newline, or null if there is no more data

Throws:

IOException - if there was an error in reading from the stream

readLine

public static String readLine(InputStream in,
                              char[] lineBuffer)
                       throws IOException

Read a line from an InputStream.

Parameters:

in - the stream to read from

lineBuffer - a buffer to use for reading the lines. Performance is better if the buffer is big enough for the longest line.

Returns:

the line read, without the newline, or null if there is no more data

Throws:

IOException - if there was an error in reading from the stream

copyFileIfNewer

public static boolean copyFileIfNewer(File sourceFile,
                                      File targetFile)

Copy a file if the source is newer than the target

Parameters:

sourceFile - the source of the copy

targetFile - the target of the copy

Returns:

false if there was a problem.

copyFile

public static boolean copyFile(File sourceFile,
                               File targetFile)

Copy the contents of a file to another file.

Parameters:

sourceFile - the source

targetFile - the target

Returns:

false if there was a problem. true otherwise.

copyFile

public static boolean copyFile(File sourceFile,
                               File targetFile,
                               char[] buffer)

Deprecated. use copyFile(File, File, byte[])

Copy the contents of a file to another file.

Parameters:

sourceFile - the source of the copy

targetFile - the target of the copy

buffer - a buffer to use for the copy

Returns:

false if there was a problem. true otherwise.

copyFile

public static boolean copyFile(File sourceFile,
                               File targetFile,
                               byte[] buffer)

Copy the contents of a file to another file.

Parameters:

sourceFile - the source of the copy

targetFile - the target of the copy

buffer - a buffer to use for the copy

Returns:

false if there was a problem. true otherwise.

readerToWriter

public static boolean readerToWriter(Reader reader,
                                     Writer writer)

Copy Reader to Writer.

Parameters:

reader - the source of the copy

writer - the destination of the copy, null if none

Returns:

false if there was a problem.

readerToWriter

public static boolean readerToWriter(Reader reader,
                                     Writer writer,
                                     char[] buffer)

Copy Reader to Writer.

Parameters:

reader - the source of the copy

writer - the destination of the copy, null if none

buffer - a buffer to use for the copy

Returns:

false if there was a problem.

spool

public static long spool(InputStream input,
                         OutputStream output,
                         byte[] buffer,
                         boolean flushOutput,
                         long length)
                  throws IOException

Copies up to length bytes from input to output using the supplied buffer.

The copying stops if input is exhausted before length bytes are copied. The actual number of bytes copied is returned.

Notes:

• This method does not close either input or output.
• Neither input or output has to be buffered--this method provides a buffer

Parameters:

input - the stream to read from

output - the stream to write to

buffer - the byte buffer to use

flushOutput - if true flush output on each write

length - the maximum number of bytes to copy

Returns:

the number of bytes copied

Throws:

IOException

spool

public static long spool(InputStream input,
                         OutputStream output,
                         byte[] buffer,
                         long length)
                  throws IOException

Copies up to length bytes from input to output using the supplied buffer.

The copying stops if input is exhausted before length bytes are copied. The actual number of bytes copied is returned.

Notes:

• This method does not close either input or output.
• Neither input or output has to be buffered--this method provides a buffer

Parameters:

input - the stream to read from

output - the stream to write to

buffer - the byte buffer to use

length - the maximum number of bytes to copy

Returns:

the number of bytes copied

Throws:

IOException

spool

public static long spool(InputStream input,
                         OutputStream output,
                         long length)
                  throws IOException

Copies up to length bytes from input to output.

The copying stops if input is exhausted before length bytes are copied. The actual number of bytes copied is returned.

Notes:

• This method does not close either input or output.
• Neither input or output has to be buffered--this method provides a buffer

Parameters:

input - the stream to read from

output - the stream to write to

length - the maximum number of bytes to copy

Returns:

the number of bytes copied

Throws:

IOException

spool

public static long spool(InputStream input,
                         OutputStream output)
                  throws IOException

Copies all the bytes from input to output.

The copying stops when input is exhausted. The actual number of bytes copied is returned.

Parameters:

input - the stream to read from

output - the stream to write to

Returns:

the number of bytes copied

Throws:

IOException

spool

public static int spool(InputStream input,
                        byte[] buffer)
                 throws IOException

Copies up to buffer.length bytes from input to buffer.

The copying stops if input is exhausted before buffer is filled. The actual number of bytes copied is returned.

Parameters:

input - the stream to read from

buffer - the byte buffer to write to

Returns:

the number of bytes copied

Throws:

IOException

inputStreamToOutputStream

public static boolean inputStreamToOutputStream(InputStream input,
                                                OutputStream output)

Copies all data from an InputStream to an OutputStream.

If you wish to use a method which throws an IOException see spool(InputStream,OutputStream).

Parameters:

input - the source of the copy

output - the destination of the copy, null if none

Returns:

false if there was a problem.

inputStreamToOutputStream

public static boolean inputStreamToOutputStream(InputStream input,
                                                OutputStream output,
                                                byte[] buffer,
                                                boolean flush)

Copies all data from an InputStream to an OutputStream.

If you wish to use a method which throws an IOException see the spool method taking the same arguments.

Parameters:

input - the source of the copy

output - the destination of the copy, null if none

buffer - a buffer to use for copying

flush - if true output is flushed after every write call

Returns:

false if there was a problem.

inputStreamToOutputStream

public static int inputStreamToOutputStream(InputStream input,
                                            OutputStream output,
                                            byte[] buffer,
                                            boolean flush,
                                            int bytesToCopy)
                                     throws IOException

Deprecated. Use spool(java.io.InputStream, java.io.OutputStream, byte[], boolean, long) instead.

Copies the specified amount of data from an InputStream to an OutputStream.

Parameters:

input - the source of the copy

output - the destination of the copy, null if none

buffer - a buffer to use for copying

flush - if true output is flushed after every write call

bytesToCopy - the number of bytes to copy

Returns:

the number of bytes copied

Throws:

IOException

bytesFromURL

public static byte[] bytesFromURL(URL url)

Read the contents of a URL as a byte array .

Parameters:

url - the URL to read

Returns:

the contents of the URL, or null if there are any problems

stringFromURL

public static String stringFromURL(URL url,
                                   String encoding)

Read the contents of a URL as a string.

Parameters:

url - the URL to read

encoding - the encoding to use (as in a String constructor). If encoding is null, we use the default encoding

Returns:

the contents of the URL, or null if there are any problems

copyUrlToFile

public static void copyUrlToFile(String sourceURLString,
                                 File targetFile)
                          throws FileNotFoundException,
                                 MalformedURLException,
                                 IOException

Copy a URL (String format) to File.

Parameters:

sourceURLString - the URL string reference source content

targetFile - the destination for the content

Throws:

FileNotFoundException

MalformedURLException

IOException

copyDirectory

public static boolean copyDirectory(File source,
                                    File target)

Copy recursively a directory Use this with caution. If an error occurs during the recursive copy, partial copying or deletion may result!

Parameters:

source - The source

target - The target

Returns:

false if there was a problem.

Throws:

NullPointerException - if one of the arguments is null

copyDirectory

public static boolean copyDirectory(File source,
                                    File target,
                                    boolean recursive,
                                    boolean createTarget)

Copy recursively a directory
Use this with caution. If an error occurs during the recursive copy, partial copying or deletion may result!

Parameters:

source - The source. It has to be a directory that exists.

target - The target

recursive - if true, will also copy the subdirectories

createTarget - if true, will create the target and its subdirectories if needed

Returns:

false if there was a problem.

Throws:

NullPointerException - if one the source or the target is null

deleteDirectory

public static boolean deleteDirectory(File dir)

Delete a directory and its subdirectories. Use this with caution. If an error occurs during the recursive delete, partial copying or deletion may result!

Parameters:

dir - Directory to delete. It has to be a directory that exists.

Returns:

false if there was a problem.

Throws:

NullPointerException - if the argument is null

getDefaultSystemEncoding

public static String getDefaultSystemEncoding()

Return the System Wide default encoding. This is not the method you are looking for, move along.

close

public static final void close(InputStream in)

Helper method to close an input stream without exceptions in a null safe manner.

Parameters:

in - the InputStream to close.

close

public static final void close(OutputStream out)

Helper method to close an output stream without exceptions in a null safe manner.

Parameters:

out - the OutputStream to close.

close

public static final void close(Reader in)

Helper method to close a Reader without exceptions in a null safe manner.

Parameters:

in - the InputStream to close.

close

public static final void close(Writer out)

Helper method to close a Writer without exceptions in a null safe manner.

Parameters:

out - the OutputStream to close.

grep

public static boolean grep(Reader reader,
                           String regex)
                    throws IOException

Greps the supplied reader character stream for regex returning true the pattern is found in the character stream and false otherwise.

Notes:

• reader is read in a line-by-line manner (there is no support currently for "across-line" matches)
• reader is advanced to the end of the first line that contains regex

Parameters:

reader - the character stream

regex - the regular expression

Throws:

IOException

grep

public static boolean grep(File file,
                           String regex,
                           Charset charset)
                    throws IOException

Returns true if the file contains a string matching regex and false otherwise.

Parameters:

file - the file

regex - the regular expression

charset - the character set used by file

Throws:

IOException

grep

public static boolean grep(File file,
                           String regex)
                    throws IOException

Returns true if the file contains a string matching regex and false otherwise.

Parameters:

file - the file (UTF-8 encoding assumed)

regex - the regular expression

Throws:

IOException

searchReplace

public static void searchReplace(Reader reader,
                                 Writer writer,
                                 String regexToFind,
                                 String toReplace)
                          throws IOException

Searches the reader character stream and replaces every occurrence of regexToFind with the replacement string toReplace. Captured groups in regexToFind can be referenced in toReplace using the standard mechanism (e.g. $1 references the first group etc.)

No support currently for across-line regexes.

This method does not close either reader or writer.

Throws:

IOException

searchReplace

public static void searchReplace(File input,
                                 Writer writer,
                                 String regexToFind,
                                 String toReplace,
                                 Charset charset)
                          throws IOException

Searches and replaces file replacing regexToFind with toReplace writing to writer.

Throws:

IOException

searchReplace

public static void searchReplace(File input,
                                 Writer writer,
                                 String regexToFind,
                                 String toReplace)
                          throws IOException

Searches and replaces input replacing regexToFind with toReplace writing to writer.

Throws:

IOException

searchReplace

public static void searchReplace(File input,
                                 File output,
                                 String regexToFind,
                                 String toReplace,
                                 Charset charset)
                          throws IOException

Searches and replaces input replacing regexToFind with toReplace writing to output.

Throws:

IOException

searchReplace

public static void searchReplace(File input,
                                 File output,
                                 String regexToFind,
                                 String toReplace)
                          throws IOException

Searches and replaces input replacing regexToFind with toReplace writing to output.

Throws:

IOException

readFirstLine

public static String readFirstLine(File file,
                                   Charset charset)
                            throws IOException

Reads and returns the first line from file using the specified charset to convert the bytes from the file into characters.

Parameters:

file - the file to read from

charset - the encoding to be used when reading the file

Returns:

the first line

Throws:

IOException

readFirstLine

public static String readFirstLine(File file)
                            throws IOException

Reads the first line from file assuming UTF-8.

Parameters:

file - the file to read from

Returns:

the first line

Throws:

IOException

writeToFile

public static void writeToFile(File file,
                               Object object,
                               boolean append,
                               Charset charset)
                        throws IOException

Writes object to file using the specified charset.

Parameters:

file - the file to write to

object - the object to write (toString() is called)

append - whether to append to the file or to truncate and write

charset - the encoding to use

Throws:

IOException

writeToFile

public static void writeToFile(File file,
                               Object object,
                               boolean append)
                        throws IOException

Writes object to file assuming UTF-8.

Parameters:

file - the file to write to

object - the object to write (toString() is called)

append - whether to append to the file or to truncate and write

Throws:

IOException