【java】网络socket编程简单示例

 package 网络编程;
 
 import java.io.IOException;
 import java.io.PrintStream;
 import java.net.ServerSocket;
 import java.net.Socket;
 
 public class TestServerSocket {
     public static void main(String[] args) throws IOException {
         ServerSocket server=new ServerSocket(9999);
         System.out.println("正在连接中……");
         Socket client=server.accept();
         PrintStream out=new PrintStream(client.getOutputStream());
         out.println("北京欢迎你。");
         out.close();
         client.close();
         server.close();
     }
 }

Server

 package 网络编程;
 
 import java.io.IOException;
 import java.net.Socket;
 import java.net.UnknownHostException;
 import java.util.Scanner;
 
 public class TestSocket {
     public static void main(String[] args) throws UnknownHostException, IOException {
         Socket client=new Socket("localhost",9999);
         Scanner scan=new Scanner(client.getInputStream());
         scan.useDelimiter("\n");
         if(scan.hasNext())
             System.out.println("响应数据："+scan.next());
         scan.close();
         client.close();
     }
 }

Client

---

echo模型：

 package 网络编程;
 
 import java.io.IOException;
 import java.io.PrintStream;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.Scanner;
 
 public class TestEchoServer {
     public static void main(String[] args) throws IOException {
         ServerSocket server = new ServerSocket(9999);
         Socket client = server.accept();
         Scanner scan = new Scanner(client.getInputStream());// 接收客户端输入
         PrintStream out = new PrintStream(client.getOutputStream());// 输出到客户端
         boolean flag = true;
         String tmp = "";
         while (flag) {
             if (scan.hasNext()) {
                 tmp = scan.next().trim();
                 if (tmp.equalsIgnoreCase("bye")) {
                     out.println("再见！");
                     flag = false;
                 } else {
                     out.println("Echo:" + tmp);
                 }
             }
         }
         out.close();
         scan.close();
         client.close();
         server.close();
     }
 }

EchoServer

 package 网络编程;
 
 import java.io.IOException;
 import java.io.PrintStream;
 import java.net.Socket;
 import java.net.UnknownHostException;
 import java.util.Scanner;
 
 public class TestEchoClient {
     public static void main(String[] args) throws UnknownHostException, IOException {
         Socket client=new Socket("localhost",9999);
         Scanner scan=new Scanner(System.in);//键盘输入
         Scanner in=new Scanner(client.getInputStream());//服务端输入
         PrintStream out=new PrintStream(client.getOutputStream());//输出到服务端
         scan.useDelimiter("\n");
 //        in.useDelimiter("\n");
         boolean flag=true;
         String msg="";
         while(flag){
             if(scan.hasNext()){//等待用户从键盘输入
                 msg=scan.next().trim();
                 out.println(msg);//信息转给服务端
                 if(msg.equalsIgnoreCase("bye"))
                     flag=false;
                 else
                     System.out.println(in.next());//打印服务端响应的信息
             }
         }
         out.close();
         in.close();
         scan.close();
         client.close();
     }
 }

EchoClient

 package 网络编程;
 
 import java.io.IOException;
 import java.io.PrintStream;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.Scanner;
 
 class ClientThread implements Runnable {
     private Socket client;
 
     public ClientThread(Socket client) {
         this.client = client;
     }
 
     @Override
     public void run() {
         try {
             Scanner scan = new Scanner(client.getInputStream());// 接收客户端输入
             PrintStream out = new PrintStream(client.getOutputStream());// 输出到客户端
             boolean flag = true;
             String tmp = "";
             while (flag) {
                 if (scan.hasNext()) {
                     tmp = scan.next().trim();
                     if (tmp.equalsIgnoreCase("bye")) {
                         out.println("再见！");
                         flag = false;
                     } else {
                         out.println("Echo:" + tmp);
                     }
                 }
             }
             out.close();
             scan.close();
             client.close();
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
 }
 
 public class TestEchoServer {
     public static void main(String[] args) throws IOException {
         ServerSocket server = new ServerSocket(9999);
         boolean flag = true;
         while (flag) {
             Socket client = server.accept();//连接多个客户端
             new Thread(new ClientThread(client)).start();//每连接一个客户端启动一个线程
         }
         server.close();
     }
 }

EchoServer多线程