ostore.util
Class QSIO

java.lang.Object
  |
  +--ostore.util.QSIO

public abstract class QSIO

extends Object

The QSIO class contains general utility methods for writing/reading QuickSerializable object to/from files.

Version:

$Id: QSIO.java,v 1.37 2003/11/17 23:52:43 emilong Exp $

Author:

Dennis Geels, Larry Tung

Constructor Summary

QSIO()

Method Summary

static QuickSerializable	bytesToQS(byte[] bytes) The inverse of qsToBytes, above.
static void	delete(RandomAccessFile file, long pos) delete the contents of a QuickSerializable by filling where the object was with 0's
static byte[]	qsToBytes(QuickSerializable object)
static QuickSerializable	read(InputStream in) Read in the QuickSerializable stored in the specified InputStream.
static QuickSerializable	read(RandomAccessFile file, long pos) Read in the QuickSerializable stored in the specified RandomAccessFile.
static QuickSerializable	read(String filename) Read in the QuickSerializable stored in the named file.
static void	write(QuickSerializable object, OutputStream out) Write a QuickSerializable object to the specified OutputStream.
static void	write(QuickSerializable object, RandomAccessFile file, long pos)
static void	write(QuickSerializable object, String filename) Write a QuickSerializable to the named file The file will be overwritten unless an IOException is thrown, in which case the file will remain unmodified.
static void	write(QuickSerializable object, String filename, boolean append) Write a QuickSerializable to the named file This method provides no guarantees against file corruption if an IOException is thrown during the write.

Methods inherited from class java.lang.Object

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

Constructor Detail

QSIO

public QSIO()

Method Detail

write

public static void write(QuickSerializable object,
                         OutputStream out)
                  throws IOException

Write a QuickSerializable object to the specified OutputStream. An 8B header is written first, containing the size of the object in bytes, followed by its type code.

Parameters:

object - The QuickSerializable object to write.

out - The OutputStream into which to write.

Throws:

IOException - if an I/O error occurs.

qsToBytes

public static byte[] qsToBytes(QuickSerializable object)

bytesToQS

public static QuickSerializable bytesToQS(byte[] bytes)
                                   throws QSException

The inverse of qsToBytes, above.

QSException

write

public static void write(QuickSerializable object,
                         String filename)
                  throws IOException

Write a QuickSerializable to the named file The file will be overwritten unless an IOException is thrown, in which case the file will remain unmodified.

Parameters:

object - The QuickSerializable object to write.

filename - The name of the file into which to write.

Throws:

IOException - if an I/O error occurs.

write

public static void write(QuickSerializable object,
                         String filename,
                         boolean append)
                  throws IOException

Write a QuickSerializable to the named file This method provides no guarantees against file corruption if an IOException is thrown during the write.

Parameters:

object - The QuickSerializable object to write.

filename - The name of the file into which to write.

append - Whether to write the object to the end of the file

Throws:

IOException - if an I/O error occurs.

write

public static void write(QuickSerializable object,
                         RandomAccessFile file,
                         long pos)
                  throws IOException

IOException

read

public static QuickSerializable read(InputStream in)
                              throws IOException,
                                     QSException

Read in the QuickSerializable stored in the specified InputStream.

Parameters:

in - The InputStream from which to read.

Returns:

the QuickSerializable read.

Throws:

IOException - if an I/O error occurs.

QSException - if in did not contain a valid QuickSerializable object.

read

public static QuickSerializable read(RandomAccessFile file,
                                     long pos)
                              throws IOException,
                                     QSException

Read in the QuickSerializable stored in the specified RandomAccessFile.

Parameters:

file - The RandomAccessFile from which to read.

pos - amount to seek to

Returns:

the QuickSerializable read.

Throws:

IOException - if an I/O error occurs.

QSException - if in did not contain a valid QuickSerializable object.

delete

public static void delete(RandomAccessFile file,
                          long pos)
                   throws IOException

delete the contents of a QuickSerializable by filling where the object was with 0's

Parameters:

pos - amount to seek to

IOException

read

public static QuickSerializable read(String filename)
                              throws IOException,
                                     QSException

Read in the QuickSerializable stored in the named file.

Parameters:

filename - The name of the file from which to read.

Returns:

the QuickSerializable read.

Throws:

IOException - if an I/O error occurs.

QSException - if in did not contain a valid QuickSerializable object.