LittleEndianDataOutputStream.java
/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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/*
* From http://www.cafeaulait.org/books/javaio/ioexamples/index.html:
*
* Please feel free to use any fragment of this code you need in your own work.
* As far as I am concerned, it's in the public domain. No permission is necessary
* or required. Credit is always appreciated if you use a large chunk or base a
* significant product on one of my examples, but that's not required either.
*
* Elliotte Rusty Harold
*/
package com.twelvemonkeys.io;
import com.twelvemonkeys.lang.Validate;
import java.io.*;
/**
* A little endian output stream writes primitive Java numbers
* and characters to an output stream in a little endian format.
* <p>
* The standard {@code java.io.DataOutputStream} class which this class
* imitates uses big endian integers.
* </p>
* <p>
* <em>Warning:
* The {@code DataInput} and {@code DataOutput} interfaces
* specifies big endian byte order in their documentation.
* This means that this class is, strictly speaking, not a proper
* implementation. However, I don't see a reason for the these interfaces to
* specify the byte order of their underlying representations.
* </em>
* <p>
*
* @see com.twelvemonkeys.io.LittleEndianRandomAccessFile
* @see java.io.DataOutputStream
* @see java.io.DataInput
* @see java.io.DataOutput
*
* @author Elliotte Rusty Harold
* @version 1.0.1, 19 May 1999
*/
public class LittleEndianDataOutputStream extends FilterOutputStream implements DataOutput {
/**
* The number of bytes written so far to the little endian output stream.
*/
protected int bytesWritten;
/**
* Creates a new little endian output stream and chains it to the
* output stream specified by the {@code pStream} argument.
*
* @param pStream the underlying output stream.
* @see java.io.FilterOutputStream#out
*/
public LittleEndianDataOutputStream(OutputStream pStream) {
super(Validate.notNull(pStream, "stream"));
}
/**
* Writes the specified byte value to the underlying output stream.
*
* @param pByte the {@code byte} value to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public synchronized void write(int pByte) throws IOException {
out.write(pByte);
bytesWritten++;
}
/**
* Writes {@code pLength} bytes from the specified byte array
* starting at {@code pOffset} to the underlying output stream.
*
* @param pBytes the data.
* @param pOffset the start offset in the data.
* @param pLength the number of bytes to write.
* @throws IOException if the underlying stream throws an IOException.
*/
public synchronized void write(byte[] pBytes, int pOffset, int pLength) throws IOException {
out.write(pBytes, pOffset, pLength);
bytesWritten += pLength;
}
/**
* Writes a {@code boolean} to the underlying output stream as
* a single byte. If the argument is true, the byte value 1 is written.
* If the argument is false, the byte value {@code 0} in written.
*
* @param pBoolean the {@code boolean} value to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeBoolean(boolean pBoolean) throws IOException {
if (pBoolean) {
write(1);
}
else {
write(0);
}
}
/**
* Writes out a {@code byte} to the underlying output stream
*
* @param pByte the {@code byte} value to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeByte(int pByte) throws IOException {
out.write(pByte);
bytesWritten++;
}
/**
* Writes a two byte {@code short} to the underlying output stream in
* little endian order, low byte first.
*
* @param pShort the {@code short} to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeShort(int pShort) throws IOException {
out.write(pShort & 0xFF);
out.write((pShort >>> 8) & 0xFF);
bytesWritten += 2;
}
/**
* Writes a two byte {@code char} to the underlying output stream
* in little endian order, low byte first.
*
* @param pChar the {@code char} value to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeChar(int pChar) throws IOException {
out.write(pChar & 0xFF);
out.write((pChar >>> 8) & 0xFF);
bytesWritten += 2;
}
/**
* Writes a four-byte {@code int} to the underlying output stream
* in little endian order, low byte first, high byte last
*
* @param pInt the {@code int} to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeInt(int pInt) throws IOException {
out.write(pInt & 0xFF);
out.write((pInt >>> 8) & 0xFF);
out.write((pInt >>> 16) & 0xFF);
out.write((pInt >>> 24) & 0xFF);
bytesWritten += 4;
}
/**
* Writes an eight-byte {@code long} to the underlying output stream
* in little endian order, low byte first, high byte last
*
* @param pLong the {@code long} to be written.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeLong(long pLong) throws IOException {
out.write((int) pLong & 0xFF);
out.write((int) (pLong >>> 8) & 0xFF);
out.write((int) (pLong >>> 16) & 0xFF);
out.write((int) (pLong >>> 24) & 0xFF);
out.write((int) (pLong >>> 32) & 0xFF);
out.write((int) (pLong >>> 40) & 0xFF);
out.write((int) (pLong >>> 48) & 0xFF);
out.write((int) (pLong >>> 56) & 0xFF);
bytesWritten += 8;
}
/**
* Writes a 4 byte Java float to the underlying output stream in
* little endian order.
*
* @param f the {@code float} value to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeFloat(float f) throws IOException {
writeInt(Float.floatToIntBits(f));
}
/**
* Writes an 8 byte Java double to the underlying output stream in
* little endian order.
*
* @param d the {@code double} value to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeDouble(double d) throws IOException {
writeLong(Double.doubleToLongBits(d));
}
/**
* Writes a string to the underlying output stream as a sequence of
* bytes. Each character is written to the data output stream as
* if by the {@link #writeByte(int)} method.
*
* @param pString the {@code String} value to be written.
* @throws IOException if the underlying stream throws an IOException.
* @see #writeByte(int)
* @see #out
*/
public void writeBytes(String pString) throws IOException {
int length = pString.length();
for (int i = 0; i < length; i++) {
out.write((byte) pString.charAt(i));
}
bytesWritten += length;
}
/**
* Writes a string to the underlying output stream as a sequence of
* characters. Each character is written to the data output stream as
* if by the {@code writeChar} method.
*
* @param pString a {@code String} value to be written.
* @throws IOException if the underlying stream throws an IOException.
* @see #writeChar(int)
* @see #out
*/
public void writeChars(String pString) throws IOException {
int length = pString.length();
for (int i = 0; i < length; i++) {
int c = pString.charAt(i);
out.write(c & 0xFF);
out.write((c >>> 8) & 0xFF);
}
bytesWritten += length * 2;
}
/**
* Writes a string of no more than 65,535 characters
* to the underlying output stream using UTF-8
* encoding. This method first writes a two byte short
* in <b>big</b> endian order as required by the
* UTF-8 specification. This gives the number of bytes in the
* UTF-8 encoded version of the string, not the number of characters
* in the string. Next each character of the string is written
* using the UTF-8 encoding for the character.
*
* @param pString the string to be written.
* @throws UTFDataFormatException if the string is longer than
* 65,535 characters.
* @throws IOException if the underlying stream throws an IOException.
*/
public void writeUTF(String pString) throws IOException {
int numchars = pString.length();
int numbytes = 0;
for (int i = 0; i < numchars; i++) {
int c = pString.charAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
numbytes++;
}
else if (c > 0x07FF) {
numbytes += 3;
}
else {
numbytes += 2;
}
}
if (numbytes > 65535) {
throw new UTFDataFormatException();
}
out.write((numbytes >>> 8) & 0xFF);
out.write(numbytes & 0xFF);
for (int i = 0; i < numchars; i++) {
int c = pString.charAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
out.write(c);
}
else if (c > 0x07FF) {
out.write(0xE0 | ((c >> 12) & 0x0F));
out.write(0x80 | ((c >> 6) & 0x3F));
out.write(0x80 | (c & 0x3F));
bytesWritten += 2;
}
else {
out.write(0xC0 | ((c >> 6) & 0x1F));
out.write(0x80 | (c & 0x3F));
bytesWritten += 1;
}
}
bytesWritten += numchars + 2;
}
/**
* Returns the number of bytes written to this little endian output stream.
* (This class is not thread-safe with respect to this method. It is
* possible that this number is temporarily less than the actual
* number of bytes written.)
* @return the value of the {@code written} field.
* @see #bytesWritten
*/
public int size() {
return bytesWritten;
}
}