两个简单的Client实例

[code="java"]import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client {
private static final String ip = "www.google.com";
private static final int port = 80;

public void start() {
try {
Socket socket = new Socket(ip, port);
OutputStream out = socket.getOutputStream();
out.write(getString().getBytes());
socket.shutdownOutput();

InputStream input = socket.getInputStream();
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
byte[] buff = new byte[1024];
int len = -1;
while ((len = input.read(buff)) != -1) {
buffer.write(buff, 0, len);
}
System.out.println(buffer.toString());
socket.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

private String getString() {
StringBuffer buffer = new StringBuffer();
buffer.append("GET / HTTP/1.1\r\n");
buffer.append("Accept: */*\r\n");
buffer.append("Accept-Language: zh-cn\r\n");
buffer.append("Accept-Encoding: gzip, deflate\r\n");
buffer.append("User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)\r\n");
buffer.append("Host: localhost\r\n");
buffer.append("Connection: Keep-Alive\r\n\r\n");
return buffer.toString();
}

public static void main(String[] args) {
new Client().start();
}
}


[code="java"]/**
* Copyright: Copyright (c) 2007
* <br>
* Company: Digifun
* <br>
* Date: Jan 6, 2010
*/
package navy.net;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;

/**
* Description:<br>
*
* @author HuangShuzhen
* @version 0.1
*/
public class Client
{
    private ByteBuffer    buffer = ByteBuffer.allocate(1024);

    private SocketChannel channel;

    private Selector      selector;

    SocketAddress         address;
   
    private boolean isRun = true;

    private void start (String host, int port)
    {
        try
        {
            channel = SocketChannel.open();
            channel.configureBlocking(false);
            address = new InetSocketAddress(host, port);
            channel.connect(address);

            selector = Selector.open();
            channel.register(selector, SelectionKey.OP_CONNECT);

            while (isRun)
            {
                if (selector.select() > 0)
                {
                    Iterator<SelectionKey> it = selector.selectedKeys().iterator();
                    while (it.hasNext())
                    {
                        SelectionKey key = it.next();
                        it.remove();
                        if (key.isConnectable())
                        {
                            System.out.println("conn");
                            channel.register(selector, SelectionKey.OP_READ | SelectionKey.OP_WRITE);
                            // 正在建立连接
                            if (channel.isConnectionPending())
                            {
                                // 完成连接
                                channel.finishConnect();
                            }
                        }
                        else if (key.isReadable())
                        {
                            System.out.println("--------------------------read-------------------");
                            read(key);
                        }
                        else if (key.isWritable())
                        {
                            System.out.println("write");
                            write(getHeader());

                        }
                    }
                }
            }
        }
        catch (UnknownHostException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }

    private byte[] read (SelectionKey key)
    {
        try
        {
            int lenght = channel.read(buffer);
            System.out.println(lenght);
            if (lenght > 0)
            {
                byte[] data = new byte[lenght];
                buffer.flip();
                buffer.get(data);
                System.out.println(new String(data));
                buffer.compact();
                buffer.clear();
            }else if(lenght ==-1){
                isRun = false;
            }

        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    private byte[] write (String content)
    {
        ByteBuffer src = ByteBuffer.wrap(content.getBytes());
        try
        {
            channel.write(src);
            channel.register(selector, SelectionKey.OP_READ);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    private String getHeader ()
    {
        StringBuffer buffer = new StringBuffer();
        buffer.append("GET /navy/ HTTP/1.1\r\n");
        buffer.append("Accept: */*\r\n");
        buffer.append("Accept-Language: zh-cn\r\n");
        buffer.append("Accept-Encoding: gzip, deflate\r\n");
        buffer.append("User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)\r\n");
        buffer.append("Host: \r\n");
        buffer.append("Connection: Keep-Alive\r\n\r\n");
        return buffer.toString();
    }

    public static void main (String[] args)
    {
        Client client = new Client();
        client.start("www.google.com", 80);
//        while(true);
    }

    private static void print (ByteBuffer buffer)
    {
        System.out.println("-----------------------------");
        System.out.println("position:" + buffer.position());
        System.out.println("limit:" + buffer.limit());
        System.out.println("capacity:" + buffer.capacity());
        System.out.println("-----------------------------");
    }
}