java Tcp通信客户端与服务器端实例

import java.io.*;
import java.net.*;
public class TestSocket {
 public static void main(String[] args) {
 try {
  ServerSocket ss = new ServerSocket(8888);
  while(true) {
  Socket s = ss.accept();
  OutputStream os = s.getOutputStream();
  DataOutputStream dos = new DataOutputStream(os);
  dos.writeUTF("hello" + s.getInetAddress() + "port" + s.getPort() + "beybye");
  dos.close();
//  os.flush();
  os.close();
//  s.close();
  }
 } catch (IOException e) {
  e.printStackTrace();
  System.out.println("there is a wrong");
 }
 }
}

import java.io.*;
import java.net.*;
public class TestClient {
 public static void main(String[] args){
 try {
  Socket s = new Socket("127.0.0.1",8888);
  DataInputStream dis = new DataInputStream(s.getInputStream());
  System.out.println(dis.readUTF()); 
  s.close();
  dis.close();
 } catch (Exception e) {
  e.printStackTrace();
 }
 }
}

import java.io.*;
import java.net.*;
public class TestClient2 {
 public static void main(String[] args){
 try {
  Socket s = new Socket("127.0.0.1",8886);
  DataOutputStream dos = new DataOutputStream(s.getOutputStream());
  DataInputStream dis = new DataInputStream(s.getInputStream());
  System.out.println(dis.readUTF()); 
  dos.writeUTF("hey");
  String str = null;
  if((str = dis.readUTF()) != null) {
  System.out.println(str);
  }
  s.close();
  dis.close();
  dos.close();
 } catch (Exception e) {
  e.printStackTrace();
 }
 }
}

public class TestServer2 {
 public static void main(String[] args) {
 InputStream in = null;
 OutputStream out = null;
 try {
  ServerSocket ss = new ServerSocket(8886);
  while(true) {
  Socket s = ss.accept();
  in = s.getInputStream();
  out = s.getOutputStream();
  DataOutputStream dos = new DataOutputStream(s.getOutputStream());
  DataInputStream dis = new DataInputStream(s.getInputStream());
  String str = null;
  if((str = dis.readUTF() )!= null) {
   System.out.println(str);
   System.out.println("form " + s.getInetAddress());
   System.out.println("port " + s.getPort());
//   dos.writeUTF("hello" + s.getInetAddress() + "port" + s.getPort() + "beybye");
  }
  dos.writeUTF("hi hello");
  dis.close();
  dos.close();
  s.close();
  }
 } catch (IOException e) {
  e.printStackTrace();
  System.out.println("there is a wrong");
 }
 }
}