timequery.java

java应用开发详解

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


public class TimeQuery 
{

	private static int port = 1111;

	private static Charset charset = Charset.forName("US-ASCII");
	private static CharsetDecoder decoder = charset.newDecoder();
	private static ByteBuffer dbuf = ByteBuffer.allocateDirect(1024);

	private static void query(String host) throws IOException 
	{
		InetSocketAddress isa = new InetSocketAddress(InetAddress.getByName(host), port);
		SocketChannel sc = null;

		try 
		{
	    		//生成一个SocketChannel
	    		sc = SocketChannel.open();
	    		//建立连接
	    		sc.connect(isa);

	    		dbuf.clear();
	    		sc.read(dbuf);

	    		dbuf.flip();
	    		//打印当前时间
	    		CharBuffer cb = decoder.decode(dbuf);
	    		System.out.print(isa + " : " + cb);

		} 
		finally 
		{
	    		if (sc != null)
			sc.close();
		}
    	}

    	public static void main(String[] args) 
    	{
		if (args.length < 1) 
		{
	    		System.err.println("Usage: java TimeQuery  host...");
	    		return;
		}
	
		int start = 0;

		for (int i = start; i < args.length; i++) 
		{
	    		String host = args[i];
	    		try 
	    		{
				query(host);
	    		} 
	    		catch (IOException e) 
	    		{
				e.printStackTrace();
	    		}
		}
    	}

}