org.fuin.utils4j

Class RandomAccessFileOutputStream

java.lang.Object

java.io.OutputStream

org.fuin.utils4j.RandomAccessFileOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class RandomAccessFileOutputStream
extends java.io.OutputStream

A random access based file output stream.

Constructor Summary

Constructors

Constructor and Description
RandomAccessFileOutputStream(java.io.File file, java.lang.String mode) Constructor with file.
RandomAccessFileOutputStream(RandomAccessFileInputStream in) Constructor with input stream.
RandomAccessFileOutputStream(RandomAccessFileOutputStream out) Constructor with output stream.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the underlying file and sets the length to the current position.
void	flush() Calls sync() of the underlying file's descriptor.
java.nio.channels.FileChannel	getChannel() Returns the channel used by the random access file.
long	getCounter() Returns the number of bytes written since start or since last call to resetCounter().
java.nio.channels.FileLock	lock(int tryLockMax, long tryWaitMillis) Lock the file.
void	resetCounter() Sets the internal counter to 0.
void	seek(long pos) Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.
void	setLength(long newLength) Sets the length of this file.
void	truncate() Sets the length of the file to the number of written bytes.
void	write(byte[] b) Writes b.length bytes from the specified byte array to this file, starting at the current file pointer.
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to the file.
void	write(int b) Writes the specified byte to this file.

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomAccessFileOutputStream

public RandomAccessFileOutputStream(java.io.File file,
                                    java.lang.String mode)
                             throws java.io.FileNotFoundException

Constructor with file.

Parameters:

file - File the stream operates on - Cannot be null.

mode - Access mode, as described in RandomAccessFile - Cannot be null.

Throws:

java.io.FileNotFoundException - If the mode is "r" but the given file object does not denote an existing regular file, or if the mode begins with "rw" but the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file.

RandomAccessFileOutputStream

public RandomAccessFileOutputStream(RandomAccessFileOutputStream out)

Constructor with output stream. The new stream shares the RandomAccessFile with the argument. Be aware that closing this stream will also close the file used by the argument!

Parameters:

out - The RandomAccessFile instance from this argument will be used - Cannot be null.

RandomAccessFileOutputStream

public RandomAccessFileOutputStream(RandomAccessFileInputStream in)

Constructor with input stream. The new stream shares the RandomAccessFile with the argument. Be aware that closing this stream will also close the file used by the argument!

Parameters:

in - The RandomAccessFile instance from this argument will be used - Cannot be null.

Method Detail

write

public final void write(int b)
                 throws java.io.IOException

Writes the specified byte to this file. The write starts at the current file pointer.

Specified by:

write in class java.io.OutputStream

Parameters:

b - the byte to be written.

Throws:

java.io.IOException - if an I/O error occurs.

write

public final void write(byte[] b)
                 throws java.io.IOException

Writes b.length bytes from the specified byte array to this file, starting at the current file pointer.

Overrides:

write in class java.io.OutputStream

Parameters:

b - the data.

Throws:

java.io.IOException - if an I/O error occurs.

write

public final void write(byte[] b,
                        int off,
                        int len)
                 throws java.io.IOException

Writes len bytes from the specified byte array starting at offset off to the file.

Overrides:

write in class java.io.OutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

java.io.IOException - If an I/O error occurs.

flush

public final void flush()
                 throws java.io.IOException

Calls sync() of the underlying file's descriptor.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException - If an I/O error occurs.

close

public final void close()
                 throws java.io.IOException

Closes the underlying file and sets the length to the current position.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException - If an I/O error occurs.

getChannel

public final java.nio.channels.FileChannel getChannel()

Returns the channel used by the random access file.

Returns:

Channel.

seek

public final void seek(long pos)
                throws java.io.IOException

Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. The offset may be set beyond the end of the file. Setting the offset beyond the end of the file does not change the file length. The file length will change only by writing after the offset has been set beyond the end of the file.

Parameters:

pos - the offset position, measured in bytes from the beginning of the file, at which to set the file pointer.

Throws:

java.io.IOException - if pos is less than 0 or if an I/O error occurs.

setLength

public final void setLength(long newLength)
                     throws java.io.IOException

Sets the length of this file.

Parameters:

newLength - The desired length of the file

Throws:

java.io.IOException - If an I/O error occurs

resetCounter

public final void resetCounter()

Sets the internal counter to 0.

getCounter

public final long getCounter()

Returns the number of bytes written since start or since last call to resetCounter().

Returns:

Number of bytes written.

truncate

public final void truncate()
                    throws java.io.IOException

Sets the length of the file to the number of written bytes. This is the same as calling setLength(getCounter()).

Throws:

java.io.IOException - Error setting the file length.

lock

public final java.nio.channels.FileLock lock(int tryLockMax,
                                             long tryWaitMillis)
                                      throws LockingFailedException

Lock the file.

Parameters:

tryLockMax - Number of tries to lock before throwing an exception.

tryWaitMillis - Milliseconds to sleep between retries.

Returns:

FileLock.

Throws:

LockingFailedException - Locking the file failed.