tee.java

JAVA网络编程技术内幕一书的源代码

/*
 * Java Network Programming, Second Edition
 * Merlin Hughes, Michael Shoffner, Derek Hamner
 * Manning Publications Company; ISBN 188477749X
 *
 * http://nitric.com/jnp/
 *
 * Copyright (c) 1997-1999 Merlin Hughes, Michael Shoffner, Derek Hamner;
 * all rights reserved; see license.txt for details.
 */

import java.io.*;

public class Tee {
  protected byte[] buffer;
  protected int bufferSize, bufferCapacity;

  public Tee (InputStream in, int initialCapacity) throws IOException {
    bufferCapacity = initialCapacity;
    buffer = new byte[bufferCapacity];
    readFrom (in);
  }

  public Tee (InputStream in) throws IOException {
    this (in, in.available () + 1);
  }

  public void readFrom (InputStream in) throws IOException {
    bufferSize = 0;
    int numberRead;
    while ((numberRead = in.read (buffer, bufferSize,
                                  bufferCapacity - bufferSize)) >= 0) {
      bufferSize += numberRead;
      if (bufferSize == bufferCapacity)
        increaseBufferSize ();
    }
  }

  protected void increaseBufferSize () {
    bufferCapacity *= 2;
    byte[] newBuffer = new byte[bufferCapacity];
    System.arraycopy (buffer, 0, newBuffer, 0, bufferSize);
    buffer = newBuffer;
  }

  public void writeTo (OutputStream out) throws IOException {
    out.write (buffer, 0, bufferSize);
  }
}