19day

day19

Tomcat

服务端

• 自定义 S

• Tomcat服务器 S：java后台开发是用别人的服务器

客户端

• 自定义 C

• 浏览器 B

UDP

发短信 不用连接 需要知道对方地址

发送端

package com.yan.lesson03;
​
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.charset.StandardCharsets;
​
//udp不需要连接服务器
public class UdpClientDemo01 {
    public static void main(String[] args) throws Exception {
        //1.建立一个socket通信
        DatagramSocket socket = new DatagramSocket();
        //2.建包
        String msg="你好啊，服务器";
        //发送给谁 IP
        InetAddress localhost = InetAddress.getByName("localhost");
        //端口号
        int port = 9090;
        //数据、发送长度起始、IP、端口
        DatagramPacket packet = new DatagramPacket(msg.getBytes(), 0, msg.getBytes().length, localhost, port);
        //3.发送包
        socket.send(packet);
        //4.关闭流
        socket.close();
    }
}

接收端

package com.yan.lesson03;
​
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
//等待客户端的连接
public class UdpServerDemo01 {
    public static void main(String[] args) throws Exception {
        //1.开放端口
        DatagramSocket socket = new DatagramSocket(9090);
        //2.接收数据  包
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);//接收
​
        socket.receive(packet);//阻塞接收
​
        System.out.println(packet.getAddress().getHostAddress());
        System.out.println(new String(packet.getData(),0, packet.getLength()));
        //关闭连接
        socket.close();
    }
}

循环发送

package com.yan.chat;
​
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.*;
import java.nio.Buffer;
​
public class UdpSenderDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(8888);
​
        //准备数据System.in
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        while (true){
            String data = reader.readLine();
            byte[] datas = data.getBytes();
            DatagramPacket packet = new DatagramPacket(datas, 0, datas.length, new InetSocketAddress("localhost",6666));
            socket.send(packet);
            if (data.equals("bye")){
                break;
            }
        }
​
        socket.close();
    }
}

接收

package com.yan.chat;
​
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;
​
public class UdpReceiveDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(6666);
​
​
        while (true){
            //准备接收包裹
            byte[] container = new byte[1024];
            DatagramPacket packet = new DatagramPacket(container,0,container.length,new InetSocketAddress("localhost",8888));
            socket.receive(packet);//阻塞式接收包裹
            //断开连接
            byte[] data = packet.getData();
            String receiveData = new String(data, 0, data.length);
            System.out.println(receiveData);
            if (receiveData.equals("bye")){
                break;
            }
​
​
        }
        socket.close();
    }
}