bytebuffer.java~

< 网络机器人java编程指南>>的配套源程序

/*
 * ByteBuffer.java
 *
 * Created on July 12, 2003, 8:30 AM
 */

package com.heaton.bot;

import java.io.*;

/**
 *
 * @author  jheaton
 */
public class ByteBuffer {
    
    public static final int INITIAL_SIZE = 32768;
    
    private byte buffer[] = new byte[INITIAL_SIZE];
    private int index = 0;
    
    public byte[]detach()
    {
        byte result[] = buffer;
        buffer = null;
        index = 0;
        return result;
    }
    
    private int capacity()
    {
        return( buffer.length-index );
    }
    
    private void expand()
    {
        byte newbuffer[] = new byte[buffer.length*2];
        System.arraycopy(buffer,0,newbuffer,0,index);
        buffer = newbuffer;
    }
    
    public void append(byte buffer[])
    {        
        System.arraycopy(buffer,0,this.buffer,index,buffer.length);
    }
    
    public void read(InputStream in,int max)
    {       
        long l = 0;
        
        do {
          int size;
          if(max!=-1)
            size = Math.min(capacity(),max);
          else
            size = capacity();
          
          l = in.read(buffer,index,capacity());
          
          if ( l<0 )
            break;
          
          if(capacity()<10)
              expand();
                    
          if(max!=-1)
          {
            max--;
            if ( max<0 )
                break;
          }
        } while ( l!=0 );
    }
}