bebufferedrandomaccessfile.java

jpeg2000编解码

/*
 * CVS Identifier:
 *
 * $Id: BEBufferedRandomAccessFile.java,v 1.1.1.1 2002/07/22 09:26:51 grosbois Exp $
 *
 * Interface:           RandomAccessIO.java
 *
 * Description:         Class for random access I/O (big-endian ordering).
 *
 *
 *
 * COPYRIGHT:
 * 
 * This software module was originally developed by Rapha雔 Grosbois and
 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
 * Askel鰂 (Ericsson Radio Systems AB); and Bertrand Berthelot, David
 * Bouchard, F閘ix Henry, Gerard Mozelle and Patrice Onno (Canon Research
 * Centre France S.A) in the course of development of the JPEG2000
 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
 * software module is an implementation of a part of the JPEG 2000
 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
 * Partners) agree not to assert against ISO/IEC and users of the JPEG
 * 2000 Standard (Users) any of their rights under the copyright, not
 * including other intellectual property rights, for this software module
 * with respect to the usage by ISO/IEC and Users of this software module
 * or modifications thereof for use in hardware or software products
 * claiming conformance to the JPEG 2000 Standard. Those intending to use
 * this software module in hardware or software products are advised that
 * their use may infringe existing patents. The original developers of
 * this software module, JJ2000 Partners and ISO/IEC assume no liability
 * for use of this software module or modifications thereof. No license
 * or right to this software module is granted for non JPEG 2000 Standard
 * conforming products. JJ2000 Partners have full right to use this
 * software module for his/her own purpose, assign or donate this
 * software module to any third party and to inhibit third parties from
 * using this software module for non JPEG 2000 Standard conforming
 * products. This copyright notice must be included in all copies or
 * derivative works of this software module.
 * 
 * Copyright (c) 1999/2000 JJ2000 Partners.
 * */
package jj2000.j2k.io;

import java.io.*;

/**
 * This class defines a Buffered Random Access File, where all I/O is
 * considered to be big-endian. It extends the
 * <tt>BufferedRandomAccessFile</tt> class.
 *
 * @see RandomAccessIO
 * @see BinaryDataOutput
 * @see BinaryDataInput
 * @see BufferedRandomAccessFile 
 * */
public class BEBufferedRandomAccessFile extends BufferedRandomAccessFile 
    implements RandomAccessIO, EndianType {
    
    /**
     * Constructor. Always needs a size for the buffer.
     * 
     * @param file The file associated with the buffer
     *
     * @param mode "r" for read, "rw" or "rw+" for read and write mode ("rw+"
     *             opens the file for update whereas "rw" removes it
     *             before. So the 2 modes are different only if the file
     *             already exists).
     *
     * @param bufferSize The number of bytes to buffer
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public BEBufferedRandomAccessFile(File file, String mode,
				      int bufferSize) throws IOException {
	super(file, mode, bufferSize);
	byteOrdering = BIG_ENDIAN;
    }
    
    /**
     * Constructor. Uses the default value for the byte-buffer size (512
     * bytes).
     * 
     * @param file The file associated with the buffer
     *
     * @param mode "r" for read, "rw" or "rw+" for read and write mode ("rw+"
     *             opens the file for update whereas "rw" removes it
     *             before. So the 2 modes are different only if the file
     *             already exists).
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public BEBufferedRandomAccessFile(File file, String mode ) 
        throws IOException {
	super(file, mode);
	byteOrdering = BIG_ENDIAN;
    }
    
    /**
     * Constructor. Always needs a size for the buffer.
     * 
     * @param name The name of the file associated with the buffer
     *
     * @param mode "r" for read, "rw" or "rw+" for read and write mode ("rw+"
     *             opens the file for update whereas "rw" removes it
     *             before. So the 2 modes are different only if the file
     *             already exists).
     *
     * @param bufferSize The number of bytes to buffer
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public BEBufferedRandomAccessFile(String name, String mode,
				      int bufferSize) throws IOException {
	super(name, mode, bufferSize);
	byteOrdering = BIG_ENDIAN;
    }
    
    /**
     * Constructor. Uses the default value for the byte-buffer size (512
     * bytes).
     * 
     * @param name The name of the file associated with the buffer
     *
     * @param mode "r" for read, "rw" or "rw+" for read and write mode ("rw+"
     *             opens the file for update whereas "rw" removes it
     *             before. So the 2 modes are different only if the file
     *             already exists).
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public BEBufferedRandomAccessFile(String name, String mode) 
        throws IOException {
	super(name, mode);
	byteOrdering = BIG_ENDIAN;
    }
    
    /**
     * Writes the short value of <tt>v</tt> (i.e., 16 least significant bits)
     * to the output. Prior to writing, the output should be realigned at the
     * byte level.
     * 
     * <p>Signed or unsigned data can be written. To write a signed value just
     * pass the <tt>short</tt> value as an argument. To write unsigned data
     * pass the <tt>int</tt> value as an argument (it will be automatically
     * casted, and only the 16 least significant bits will be written).</p>
     * 
     * @param v The value to write to the output
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final void writeShort(int v) throws IOException {
	write(v>>>8);
	write(v);
    }
    
    /**
     * Writes the int value of <tt>v</tt> (i.e., the 32 bits) to the
     * output. Prior to writing, the output should be realigned at the byte
     * level.
     * 
     * @param v The value to write to the output
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final void writeInt(int v)throws IOException {
 	write(v>>>24);
 	write(v>>>16);
	write(v>>>8);
	write(v);
    }
    
    /**
     * Writes the long value of <tt>v</tt> (i.e., the 64 bits) to the
     * output. Prior to writing, the output should be realigned at the byte
     * level.
     * 
     * @param v The value to write to the output
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final void writeLong(long v) throws IOException {
	write((int)(v>>>56));
	write((int)(v>>>48));
 	write((int)(v>>>40));
	write((int)(v>>>32));
	write((int)(v>>>24));
	write((int)(v>>>16));
 	write((int)(v>>>8));
	write((int)v);
    }
    
    /**
     * Writes the IEEE float value <tt>v</tt> (i.e., 32 bits) to the
     * output. Prior to writing, the output should be realigned at the byte
     * level.
     * 
     * @param v The value to write to the output
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final void writeFloat(float v) throws IOException {
	int intV = Float.floatToIntBits(v);
	
	write(intV>>>24);
	write(intV>>>16);
	write(intV>>>8);
	write(intV);
    }
    
    /**
     * Writes the IEEE double value <tt>v</tt> (i.e., 64 bits) to the
     * output. Prior to writing, the output should be realigned at the byte
     * level.
     * 
     * @param v The value to write to the output
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final void writeDouble(double v) throws IOException {
	long longV = Double.doubleToLongBits(v);
	
	write((int)(longV>>>56));
	write((int)(longV>>>48));
	write((int)(longV>>>40));
	write((int)(longV>>>32));
	write((int)(longV>>>24));
	write((int)(longV>>>16));
	write((int)(longV>>>8));
	write((int)(longV));
    }
    
    /**
     * Reads a signed short (i.e. 16 bit) from the input. Prior to reading,
     * the input should be realigned at the byte level.
     * 
     * @return The next byte-aligned signed short (16 bit) from the input.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final short readShort() throws IOException, EOFException {
	return (short)( (read()<<8) | (read()) );
    }
    
    /**
     * Reads an unsigned short (i.e., 16 bit) from the input. It is returned
     * as an <tt>int</tt> since Java does not have an unsigned short
     * type. Prior to reading, the input should be realigned at the byte
     * level.
     * 
     * @return The next byte-aligned unsigned short (16 bit) from the input,
     * as an <tt>int</tt>.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final int readUnsignedShort() throws IOException, EOFException {
	return ( (read()<<8) | read() );
    }
    
    /**
     * Reads a signed int (i.e., 32 bit) from the input. Prior to reading, the
     * input should be realigned at the byte level.
     * 
     * @return The next byte-aligned signed int (32 bit) from the input.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final int readInt() throws IOException, EOFException {
	return ( (read()<<24) | (read()<<16) | (read()<<8) | read() );
    }
    
    /**
     * Reads an unsigned int (i.e., 32 bit) from the input. It is returned as
     * a <tt>long</tt> since Java does not have an unsigned short type. Prior
     * to reading, the input should be realigned at the byte level.
     * 
     * @return The next byte-aligned unsigned int (32 bit) from the input, as
     * a <tt>long</tt>.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final long readUnsignedInt() throws IOException, EOFException {
	return (long)( (read()<<24) | (read()<<16) | (read()<<8) | read() );
    }
    
    /**
     * Reads a signed long (i.e., 64 bit) from the input. Prior to reading,
     * the input should be realigned at the byte level.
     * 
     * @return The next byte-aligned signed long (64 bit) from the input.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final long readLong() throws IOException, EOFException {
	return ( ((long)read()<<56) | ((long)read()<<48) | ((long)read()<<40)|
		((long)read()<<32) | ((long)read()<<24) | ((long)read()<<16)|
		((long)read()<<8) | ((long)read()) );
    }
    
    /**
     * Reads an IEEE single precision (i.e., 32 bit) floating-point number
     * from the input. Prior to reading, the input should be realigned at the
     * byte level.
     * 
     * @return The next byte-aligned IEEE float (32 bit) from the input.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final float readFloat() throws EOFException, IOException {
	return Float.intBitsToFloat( (read()<<24) | (read()<<16)|
                                     (read()<<8) | (read()) );
    }
    
    /**
     * Reads an IEEE double precision (i.e., 64 bit) floating-point number
     * from the input. Prior to reading, the input should be realigned at the
     * byte level.
     * 
     * @return The next byte-aligned IEEE double (64 bit) from the input.
     *
     * @exception java.io.EOFException If the end-of file was reached before
     * getting all the necessary data.
     *
     * @exception java.io.IOException If an I/O error ocurred.
     * */
    public final double readDouble() throws IOException, EOFException {
	return Double.longBitsToDouble( ((long)read()<<56)|
                                        ((long)read()<<48)|
                                        ((long)read()<<40)|
                                        ((long)read()<<32)|
                                        ((long)read()<<24)|
                                        ((long)read()<<16)|
                                        ((long)read()<<8)|
                                        ((long)read()) );
    }
    
    /**
     * Returns a string of information about the file and the endianess 
     * */
    public String toString(){
	return super.toString()+"\nBig-Endian ordering";
    }
}