socketconnectioninputstream.java

一个实用工具类

/*
 * Copyright (C) butor.com. All rights reserved.
 *
 * This software is published under the terms of the GNU Library General
 * Public License (GNU LGPL), a copy of which has been included with this
 * distribution in the LICENSE.txt file. 
 */


package org.butor.socket.tcp;

import java.io.IOException;
import java.io.InputStream;

/**
 * Implementation of InputStream on object SocketConnection.
 * It is usefull to provide InputStream capabilities on object
 * as SocketConnection where read/write timeouts are managed
 * and events dispatiching are provided.
 * 
 * @author Aiman Sawan
 */
public class SocketConnectionInputStream extends InputStream {

	protected SocketConnection f_conn;

	// to perform one byte write in write(byte).
	protected byte[] f_oneByteArray;

	/**
	 * Constructor for SocketConnectionInputStream.
	 */
	public SocketConnectionInputStream(SocketConnection conn) throws IOException {
		super();
		
		if (conn == null) {
			throw new IOException("Got NULL SocketConnection object!");
		}
		
		f_conn = conn;
		f_oneByteArray = new byte[1];
	}

	/**
	 * @see InputStream#read()
	 */
	public int read() throws IOException {
		if (f_conn.read(f_oneByteArray) > 0) {
			return f_oneByteArray[0];
		} else {
			return 0;
		}
	}

	/**
	 * @see InputStream#read(byte[])
	 */
	public int read(byte[] buffer) throws IOException {
		return f_conn.read(buffer);
	}

	/**
	 * read buffer of bytes.
	 * Make one fast read without timeout mecanics.
	 * This is usefull to drain unwanted still bytes.
	 * If nothing to be read by 1/1000 of second it will
	 * be ok.
	 * 
	 * @param buffer byte[], buffer to fill
	 * 
	 * @return int, number of read bytes.
	 */
	public int readFast(byte[] buffer) throws IOException {
		return f_conn.readFast(buffer);
	}

	/**
	 * @see InputStream#read(byte[], int offset, int count)
	 */
	public int read(byte[] buffer, int offset, int count) throws IOException {
		return f_conn.read(buffer, offset, count);
	}

	/**
	 * @see InputStream#available()
	 */
	public int available() throws IOException {
		return 0;
	}
	
	/**
	 * @see InputStream#skip(long)
	 */
	public long skip(long count) throws IOException {
		// not supported
		return 0;
	}

	/**
	 * @see InputStream#close()
	 */
	public void close() throws IOException {
		f_conn.disconnect();
	}
	
	/**
	 * @see InputStream#mark()
	 */
	public synchronized void mark() {
		// not supported
	}
	
	/**
	 * @see InputStream#markSupported()
	 */
	public boolean markSupported() {
		return false;
	}
	
	/**
	 * @see InputStream#reset()
	 */
	public void reset() throws IOException {
		// not supported
	}	
}