[Java]UDP通信的简单例子
最后更新于：2022-04-01 09:59:21
~~~
package com.sjf;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketException;
/**
* @time 2015-05-27
* @desc UDP通信
* @author sjf0115
*
*/
public class Server {
private byte[] buffer = new byte[1024];
private DatagramSocket socket = null;
private DatagramPacket packet = null;
private InetSocketAddress socketAddress = null;
private InetAddress clientAddress;
private String clientIP;
private int clientPort;
private String clientData;
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 构造函数，绑定主机和端口.
* @param ip IP 地址
* @param port 端口
* @throws Exception
*/
public Server(String ip, int port) throws Exception
{
// 绑定IP地址和端口.
Bind(ip,port);
System.out.println("[服务端启动]");
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public Server() throws SocketException
{
// 构造数据报套接字并将其绑定到本地主机上任何可用的端口
socket = new DatagramSocket();
System.out.println("[服务端启动]");
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 绑定监听地址和端口.
* @param ip IP地址
* @param port 端口
* @throws SocketException
*/
public void Bind(String ip, int port) throws SocketException {
// 根据 IP 地址和端口号创建套接字地址
socketAddress = new InetSocketAddress(ip, port);
// 创建数据报套接字，将其绑定到指定的本地地址
socket = new DatagramSocket(socketAddress);
packet = new DatagramPacket(buffer, buffer.length);
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public final String getOrgIp()
{
return clientIP;
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 设置超时时间
* @param timeout 超时时间
* @throws Exception
*/
public void SetTimeout(int timeout) throws Exception
{
/* 启用/禁用带有指定超时值的 SO_TIMEOUT，以毫秒为单位。
* 将此选项设为非零的超时值时，对此 DatagramSocket 调用 receive() 将只阻塞此时间长度。
* 如果超过超时值，将引发 java.net.SocketTimeoutException，虽然 DatagramSocket 仍旧有效。
* 选项必须在进入阻塞操作前被启用才能生效。
*/
socket.setSoTimeout(timeout);
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 获得超时时间.
* @return 返回超时时间.
* @throws Exception
*/
public int GetTimeout() throws Exception
{
return socket.getSoTimeout();
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 接收数据包，该方法会造成线程阻塞.
* @return 返回接收的数据串信息
* @throws IOException
*/
public String Receive() throws IOException
{
/*
* 从此套接字接收数据报包。当此方法返回时，DatagramPacket 的缓冲区填充了接收的数据。
* 数据报包也包含发送方的 IP 地址和发送方机器上的端口号。此方法在接收到数据报前一直阻塞。
* 数据报包对象的 length 字段包含所接收信息的长度。如果信息比包的长度长，该信息将被截短。
*/
socket.receive(packet);
// 数据报包包含发送方的 IP 地址
clientAddress = packet.getAddress();
clientIP = clientAddress.getHostAddress();
// 数据报包包含发送方的端口号
clientPort = packet.getPort();
// 数据报包包含发送方的数据
clientData = new String(packet.getData(), 0, packet.getLength());
return " ["+clientData+"]";
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 将响应包发送给请求端.
* @param bytes 回应报文
* @throws IOException
*/
public void Send(String info) throws IOException
{
packet.setAddress(clientAddress);
packet.setPort(clientPort);
packet.setData(info.getBytes());
/*
* 从此套接字发送数据报包。DatagramPacket 包含的信息指示：将要发送的数据、其长度、远程主机的 IP 地址和远程主机的端口号。
*/
socket.send(packet);
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 关闭udp监听口.
*/
public void close()
{
try
{
socket.close();
}
catch (Exception ex)
{
ex.printStackTrace();
}
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 测试方法.
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
String serverHost = "127.0.0.1";
int serverPort = 3344;
Server udpServerSocket = new Server(serverHost, serverPort);
while (true)
{
String info = udpServerSocket.Receive();
System.out.println("["+udpServerSocket.clientPort+"]->"+info);
udpServerSocket.Send("Reponse-----"+info);
}
}
}
~~~
~~~
package com.sjf;
import java.io.*;
import java.net.*;
/**
* @time 2015-05-27
* @desc UDP通信
* @author QPING
*/
public class Client {
private byte[] buffer = new byte[1024];
private DatagramSocket socket = null;
private InetSocketAddress socketAddress = null;
private String clientIP;
private int clientPort;
private String clientData;
private InetAddress clientAddress;
private DatagramPacket sendPacket;
private DatagramPacket receivePacket;
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public Client(String host, int port) throws Exception
{
// 根据 IP 地址和端口号创建套接字地址
socketAddress = new InetSocketAddress(host, port);
// 创建数据报套接字，将其绑定到指定的本地地址
socket = new DatagramSocket(socketAddress);
System.out.println("服务端启动!");
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 构造函数，创建UDP客户端
* @throws Exception
*/
public Client() throws Exception
{
socket = new DatagramSocket();
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 设置超时时间，该方法必须在bind方法之后使用.
* @param timeout 超时时间
* @throws Exception
*/
public final void SetTimeout(final int timeout) throws Exception
{
socket.setSoTimeout(timeout);
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 获得超时时间.
* @return 返回超时时间
* @throws Exception
*/
public int GetTimeout() throws Exception
{
return socket.getSoTimeout();
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
public DatagramSocket GetSocket()
{
return socket;
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 向指定的服务端发送数据信息.
* @param ip 服务器主机地址
* @param port 服务端端口
* @param bytes 发送的数据信息
* @return 返回构造后俄数据报
* @throws IOException
*/
public DatagramPacket Send(String ip,int port,String info) throws IOException
{
byte[] bytes = info.getBytes();
sendPacket = new DatagramPacket(bytes, bytes.length);
sendPacket.setAddress(InetAddress.getByName(ip));
sendPacket.setPort(port);
socket.send(sendPacket);
return sendPacket;
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 接收从指定的服务端发回的数据.
* @param lhost 服务端主机
* @param lport 服务端端口
* @return 返回从指定的服务端发回的数据.
* @throws Exception
*/
public String Receive(String lhost,int lport) throws Exception
{
receivePacket = new DatagramPacket(buffer, buffer.length);
socket.receive(receivePacket);
// 数据报包包含发送方的 IP 地址
clientAddress = receivePacket.getAddress();
clientIP = clientAddress.getHostAddress();
// 数据报包包含发送方的端口号
clientPort = receivePacket.getPort();
// 数据报包包含发送方的数据
clientData = new String(receivePacket.getData(), 0, receivePacket.getLength());
return "["+clientData+"]";
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 关闭udp连接.
*/
public void close()
{
try
{
socket.close();
}
catch (Exception ex)
{
ex.printStackTrace();
}
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/**
* 测试客户端发包和接收回应信息的方法.
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
String serverHost = "127.0.0.1";
int serverPort = 3344;
String myIP = "127.0.0.2";
int myPort = 3333;
Client client = new Client(myIP,myPort);
while(true)
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("["+myPort+"] ");
String str = br.readLine();
client.Send(serverHost, serverPort, str);
String info = client.Receive(serverHost, serverPort);
System.out.println("["+client.clientPort+"]->" + info);
}
}
}
~~~