com.sun.jini.reliableLog

Class LogInputStream

java.lang.Object

java.io.InputStream

com.sun.jini.reliableLog.LogInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class LogInputStream
extends InputStream

This class extends the functionality of the java.io.InputStream class in order to provide an input mechanism that can be used by processes that perform logging operations; in particular, processes that store state in order to provide persistence.

Author:

Sun Microsystems, Inc.

See Also:

InputStream

Field Summary

Fields

Modifier and Type	Field and Description
private InputStream	in
private int	length

Constructor Summary

Constructors

Constructor and Description
LogInputStream(InputStream in, int length) Creates a log input file with the specified input stream.

Method Summary

Methods

Modifier and Type	Method and Description
int	available() Returns the number of bytes that can be read without blocking.
private void	badRead(int numBytes) Throw exception for reading past end of log record.
void	close() Closes the input stream.
protected void	finalize() Closes the stream when garbage is collected.
int	read() Reads a byte of data.
int	read(byte[] b) Reads data into an array of bytes.
int	read(byte[] b, int off, int len) Reads data into an array of bytes.
long	skip(long n) Skips n bytes of input.

Methods inherited from class java.io.InputStream

mark, markSupported, reset

Methods inherited from class java.lang.Object

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

Field Detail

in

private InputStream in

length

private int length

Constructor Detail

LogInputStream

public LogInputStream(InputStream in,
              int length)
               throws IOException

Creates a log input file with the specified input stream.

Parameters:

in - the input stream

length - the total number of bytes allowed to be read

Throws:

IOException - If an I/O error has occurred.

Method Detail

badRead

private void badRead(int numBytes)
              throws LogException

Throw exception for reading past end of log record.

Parameters:

numBytes - number of bytes attempted to be read

Throws:

LogException - Attempt to read past end of log.

read

public int read()
         throws IOException,
                LogException

Reads a byte of data. This method will block if no input is available.

Specified by:

read in class InputStream

Returns:

the byte read, or -1 if the end of the stream is reached

Throws:

LogException - Attempt to read past end of log.

IOException - If an I/O error has occurred.

read

public int read(byte[] b)
         throws IOException,
                LogException

Reads data into an array of bytes. This method blocks until some input is available.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read

Returns:

the actual number of bytes read, -1 is returned when the end of the stream is reached

Throws:

LogException - Attempt to read past end of log.

IOException - If an I/O error has occurred.

read

public int read(byte[] b,
       int off,
       int len)
         throws IOException,
                LogException

Reads data into an array of bytes. This method blocks until some input is available.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read

off - the start offset of the data

len - the maximum number of bytes read

Returns:

the actual number of bytes read, -1 is returned when the end of the stream is reached

Throws:

LogException - Attempt to read past end of log.

IOException - If an I/O error has occurred.

skip

public long skip(long n)
          throws IOException,
                 LogException

Skips n bytes of input.

Overrides:

skip in class InputStream

Parameters:

n - the number of bytes to be skipped

Returns:

the actual number of bytes skipped

Throws:

LogException - Attempt to read past end of log.

IOException - If an I/O error has occurred.

available

public int available()

Returns the number of bytes that can be read without blocking.

Overrides:

available in class InputStream

Returns:

the number of available bytes, which is initially equal to the file size

close

public void close()

Closes the input stream. No further input can be read.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

finalize

protected void finalize()
                 throws IOException

Closes the stream when garbage is collected.

Overrides:

finalize in class Object

Throws:

IOException