客户端:TestTCPClient.java
package net;

import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

public class TestTCPClient 
{
    public static void main(String[] args) 
    {
        try
        {
            Socket s = new Socket("127.0.0.1",6767);
            DataOutputStream dos = new DataOutputStream(s.getOutputStream());
            dos.writeUTF("Hello I am bulktree");
            dos.flush();
            dos.close();
            s.close();
        }
        catch(UnknownHostException ue)
        {
            ue.printStackTrace();
        }
        catch(IOException ie)
        {
            ie.printStackTrace();
        }
        
    }
}

服务端TestTCPServet.java
package net;

import java.io.DataInputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class TestTCPServer 
{
    public static void main(String[] args) 
    {
        try
        {
            ServerSocket ss = new ServerSocket(6767);
            Socket s = ss.accept();
            System.out.println("A Client Connection!");
            DataInputStream dis = new DataInputStream(s.getInputStream());
            System.out.println(dis.readUTF());
            dis.close();
            s.close();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
        
    }
}