nonblockclient.java

Java Non Block Client sokcet

import java.nio.*;
import java.nio.channels.*;
import java.net.*;
import java.io.*;
import java.nio.channels.spi.*;
import java.nio.charset.*;
import java.lang.*;


public class Client
{
    public SocketChannel client = null;
    public InetSocketAddress isa = null;
    public RecvThread rt = null;

    public Client()
    {
    }
    
	public void makeConnection()
    {
		int result = 0;
		try
		{
			
			client = SocketChannel.open();
				isa = new InetSocketAddress("nicholson",4900);
			client.connect(isa);
			client.configureBlocking(false);
			receiveMessage();    
		}
		catch(UnknownHostException e)
		{
			e.printStackTrace();
		}
		catch(IOException e)
		{
			e.printStackTrace();
		}
		while ((result = sendMessage()) != -1)
		{
		}

		try
		{
			client.close();
			System.exit(0);
		}
		catch(IOException e)
		{
			e.printStackTrace();
		}
    }
    
	public int sendMessage()
    {
		System.out.println("Inside SendMessage");
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		String msg = null;
		ByteBuffer bytebuf = ByteBuffer.allocate(1024);
		int nBytes = 0;
		try
		{
			msg = in.readLine();
			System.out.println("msg is "+msg);
			bytebuf = ByteBuffer.wrap(msg.getBytes());
			nBytes = client.write(bytebuf);
			System.out.println("nBytes is "+nBytes);
			if (msg.equals("quit") || msg.equals("shutdown")) {
				System.out.println("time to stop the client");
				interruptThread();
				try
				{
					Thread.sleep(5000);
				}
				catch(Exception e)
				{
					e.printStackTrace();
				}
				client.close();
				return -1;
			}	    
		}
        catch(IOException e)
		{
			e.printStackTrace();
		}
		System.out.println("Wrote "+nBytes +" bytes to the server");
		return nBytes;
    }

    public void receiveMessage()
    {
		rt = new RecvThread("Receive THread",client);
		rt.start();

    }

    public void interruptThread()
    {
		rt.val = false;
    }

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

    public class RecvThread extends Thread
    {
		public SocketChannel sc = null;
		public boolean val = true;
	
		public RecvThread(String str,SocketChannel client)
		{
			super(str);
			sc = client;
		}
	
		public void run() {

			System.out.println("Inside receivemsg");
			int nBytes = 0;
			ByteBuffer buf = ByteBuffer.allocate(2048);
			try
			{
				while (val)
				{
					while ( (nBytes = nBytes = client.read(buf)) > 0){
						buf.flip();
						Charset charset = Charset.forName("us-ascii");
						CharsetDecoder decoder = charset.newDecoder();
						CharBuffer charBuffer = decoder.decode(buf);
						String result = charBuffer.toString();
									System.out.println(result);
						buf.flip();
						
					}
				}
			
			}
			catch(IOException e)
			{
				e.printStackTrace();
			
			} 
		}
    }
}