【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();
    }
}

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("
");
        if(scan.hasNext())
            System.out.println("响应数据："+scan.next());
        scan.close();
        client.close();
    }
}

---

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();
    }
}

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("
");
//        in.useDelimiter("
");
        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();
    }
}

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();
    }
}