java 网络编程基础 UDP协议DatagramSocket,MulticastSocket 实现局域网聊天软件(Server + Client模式)

package tcpandudp.udpexample;import java.io.IOException;
import java.net.*;/**
* @ClassName MulticastServerScoket
* @projectName: object1
* @author: Zhangmingda
* @description： 设计思想：为避免所有人直接发广播，导致消息内容无环节把控，消息发送的时候，发送到非广播端口(作为一个服务端)再由此服务端向广播地址发送消息，
* date: 2021/5/13.
*/
public class MulticastServerScoket {
/**
* 广播Socket端口
*/
private static final int BROAD_PORT = 30000;
/**
* 广播IP地址 ：224.0.0.0 到 239.255.255.255
*/
private static final String BROAD_IP = "230.3.3.3";
/**
* 服务端口
*/
private static final int SERVER_PORT = 8888;
private void start(){
try (
/**
* 广播用套接字
*/
MulticastSocket multicastSocket = new MulticastSocket(BROAD_PORT);
/**
* 服务端套接字
*/
DatagramSocket datagramSocket = new DatagramSocket(SERVER_PORT)
){
/**
* 广播IP地址
*/
InetAddress multi_addr = InetAddress.getByName(BROAD_IP);
/**
* 广播套接字配置接收广播的IP地址
*/
multicastSocket.joinGroup(multi_addr);
/**
* 构建接收UDP数据的包
*/
byte[] inBuff = new byte[4096];
DatagramPacket inPacket = new DatagramPacket(inBuff,inBuff.length);
/**
* 接收广播，并广播出去
*/
while (true){
//普通套接字收广播
datagramSocket.receive(inPacket); String content = new String(inPacket.getData(),0,inPacket.getLength());
System.out.println(content);
//广播套接字发广播
DatagramPacket outPacket = new DatagramPacket(inPacket.getData(),inPacket.getLength(),multi_addr,BROAD_PORT);
multicastSocket.send(outPacket);
}
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 程序入口
*/
public static void main(String[] args) {
new MulticastServerScoket().start();
}
}

package tcpandudp.udpexample;import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.*;
import java.util.Scanner;
import java.util.concurrent.atomic.AtomicReference;/**
* @ClassName MulticastClientSocket
* @projectName: object1
* @author: Zhangmingda
* @description： XXX
* date: 2021/5/13.
*/
public class MulticastClientSocket {
/**
* 广播Socket端口
*/
private static final int BROAD_PORT = 30000;
/**
* 广播IP地址 ：224.0.0.0 到 239.255.255.255
*/
private static final String BROAD_IP = "230.3.3.3"; /**
* 要发送数据包的服务端IP地址和 端口
*/
private static final String SERVER_IP = "127.0.0.1";
private static final int SERVER_PORT = 8888; private void go() {
JFrame jFrame = new JFrame("广播聊天客户端");
//上部
JPanel topPanel = new JPanel();
JTextField topTextField = new JTextField(30);
JButton topButton = new JButton("确认用户名");
topPanel.add(topTextField);
topPanel.add(topButton);
jFrame.add(topPanel, BorderLayout.NORTH);
//中部
JTextArea centerArea = new JTextArea(10,40);
JScrollPane centerPane = new JScrollPane(centerArea);
jFrame.add(centerPane);
//下
JPanel bottomPanel = new JPanel();
JTextField bottomTextField = new JTextField(35);
JButton sendButton = new JButton("发送");
bottomPanel.add(bottomTextField);
bottomPanel.add(sendButton);
jFrame.add(bottomPanel, BorderLayout.SOUTH); jFrame.setLocation(400,300);
jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
jFrame.pack();
jFrame.setVisible(true);
AtomicReference<String> username = new AtomicReference<>("");
//确认用户名事件监听器
Action confirmListener = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent actionEvent) {
String topTextContent = topTextField.getText();
if (topTextContent != null && ! "".equals(topTextContent)){
username.set(topTextContent);
System.out.println("用户名设置成功");
}
}
};
//绑定事件监听器
topButton.addActionListener(confirmListener);
topTextField.getInputMap().put(KeyStroke.getKeyStroke('\n'),"confirm_username");
topTextField.getActionMap().put("confirm_username",confirmListener);
/**
* 发送&接收用socket
*/
try{
MulticastSocket mClinetSocket = new MulticastSocket(BROAD_PORT);
InetAddress multi_addr = InetAddress.getByName(BROAD_IP);
/**
* 接收端
*/
new Thread(){
@Override
public void run() {
byte[] inBuff = new byte[4096];
/**
* 构建接收包
*/
DatagramPacket inPacket = new DatagramPacket(inBuff,0,inBuff.length);
while (true){
/**
* 接收数据放包里,转为字符串打印出来
*/
try {
mClinetSocket.receive(inPacket);
} catch (IOException e) {
e.printStackTrace();
}
String content = new String(inPacket.getData(),0, inPacket.getLength());
System.out.println(content);
centerArea.append(content + "\n"); //向文本框加入文本
}
}
}.start();
/**
* 套接字加入广播地址
*/
mClinetSocket.joinGroup(multi_addr); /**
* 服务端地址构建
*/
InetAddress server_addr = InetAddress.getByName(SERVER_IP);
/**
* 构建发出包
*/
DatagramPacket outPacket = new DatagramPacket(new byte[0],0,server_addr,SERVER_PORT);
/**
* 发送按钮监听器
*/
Action sendListener = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent actionEvent) {
if (username.get().equals("")){
System.err.println("请输入用户名");
}else {
String sendContent = bottomTextField.getText();
if (sendContent != null && ! "".equals(sendContent)){
sendContent = username + "：" + sendContent;
//输入字节存入包，
outPacket.setData(sendContent.getBytes());
try {
mClinetSocket.send(outPacket);
bottomTextField.setText(null);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
};
/**
* 发送按钮绑定监听器
*/
sendButton.addActionListener(sendListener);
//内容框监听键盘
bottomTextField.getInputMap().put(KeyStroke.getKeyStroke('\n'),"send");
bottomTextField.getActionMap().put("send",sendListener);
} catch (IOException e) {
e.printStackTrace();
} } public static void main(String[] args) {
new MulticastClientSocket().go();
}
}