bytewriter.java

来自「JRemoteControl is a simple Java&#8482 dr」· Java 代码 · 共 104 行

/*
 * JRemCntl - Copyright (C) 2007 Filippo Di Vattimo <[e-mail]>
 * See COPYING
 */

package fildiv.jremcntl.common.proto;

import java.io.UnsupportedEncodingException;

import fildiv.jremcntl.common.core.JRemRuntimeException;

public class ByteWriter {

	private int offset; 
	private byte[] bytes;

	public ByteWriter() {
		this.bytes = null;
	}

	public ByteWriter(byte[] data) {
		this.bytes = data;
	}
	
	public void setBytes(byte[] bytes) {
		this.bytes = bytes;
		offset = 0;
	}
	
	protected void safeOffsetAdd(int offset) {
		
		this.offset += offset;
		
		if (bytes != null && this.offset > bytes.length)
			throw new IndexOutOfBoundsException();
		
	}
	
	public void append(byte[] b2) {
		
		if (bytes != null) {
			for (int index = 0; index < b2.length; ++index) {
				bytes[offset + index] = b2[index];
			}
		}
			
		safeOffsetAdd(b2.length);
	}
	
	public void addShort(short value) {
		
		if (bytes != null) {
			bytes[offset] = (byte) ((value >> 8) & 0xff);
			bytes[offset + 1] = (byte) (value & 0xff);
		}
		
		safeOffsetAdd(JRemAbstractProtocol.LENGHT_SHORT);
	}
	
	public void addInt(int value) {
		
		if (bytes != null) {
			bytes[offset] = (byte) ((value >> 24) & 0xff);
			bytes[offset + 1] = (byte) ((value >> 16) & 0xff);
			bytes[offset + 2] = (byte) ((value >> 8) & 0xff);
			bytes[offset + 3] = (byte) (value & 0xff);

		}
		
		safeOffsetAdd(JRemAbstractProtocol.LENGHT_INT);
	}
	
	public void addString(String value) {
		
		// len & value
		
		byte[] bytes = null;
				
		try {
			bytes = value.getBytes("UTF-8");
		} catch (UnsupportedEncodingException e) {
			throw new JRemRuntimeException(e);
		}
		
		addInt(value.length());
		append(value.getBytes());
	}	
	
	public byte[] getBytes() {
		return bytes;
	}
	
	public int getSize() {
		return offset;
	}
	
	public int getBufferLenght() {
		if (bytes == null)
			return 0;
		
		return bytes.length;
	}
}