十三、Socket编程实现TCP和UDP

1.TCP

（1）TCPServer.java类

package com.interview.javabasic.socket;import com.interview.javabasic.thread.MyThread;import .ServerSocket;import .Socket;public class TCPServer {public static void main(String[] args) throws Exception {//创建socket,并将socket绑定到65000端口ServerSocket ss = new ServerSocket(65000);//死循环，使得socket一直等待并处理客户端发送过来的请求while (true) {//监听65000端口，直到客户端返回连接信息后才返回Socket socket = ss.accept();//获取客户端的请求信息后，执行相关业务逻辑new LengthCalculator(socket).start();}}}

（2）TCPClient.java

package com.interview.javabasic.socket;import java.io.InputStream;import java.io.OutputStream;import .Socket;public class TCPClient {public static void main(String[] args) throws Exception {//创建socket，并指定连接的是本机的端口号为65000的服务器socketSocket socket = new Socket("127.0.0.1", 65000);//获取输出流OutputStream os = socket.getOutputStream();//获取输入流InputStream is = socket.getInputStream();//将要传递给server的字符串参数转换成byte数组，并将数组写入到输出流中os.write(new String("hello world").getBytes());int ch = 0;byte[] buff = new byte[1024];//buff主要用来读取输入的内容，存成byte数组，ch主要用来获取读取数组的长度ch = is.read(buff);//将接收流的byte数组转换成字符串，这里是从服务端回发回来的字符串参数的长度String content = new String(buff, 0, ch);System.out.println(content);//不要忘记关闭输入输出流以及socket is.close();os.close();socket.close();}}

（3）LengthCalculator.java

package com.interview.javabasic.socket;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import .Socket;public class LengthCalculator extends Thread {//以socket为成员变量private Socket socket;public LengthCalculator(Socket socket) {this.socket = socket;}@Overridepublic void run() {try {//获取socket的输出流OutputStream os = socket.getOutputStream();//获取socket的输入流InputStream is = socket.getInputStream();int ch = 0;byte[] buff = new byte[1024];//buff主要用来读取输入的内容，存成byte数组，ch主要用来获取读取数组的长度ch = is.read(buff);//将接收流的byte数组转换成字符串，这里获取的内容是客户端发送过来的字符串参数String content = new String(buff, 0, ch);System.out.println(content);//往输出流里写入获得的字符串的长度，回发给客户端 os.write(String.valueOf(content.length()).getBytes());//不要忘记关闭输入输出流以及socket is.close();os.close();socket.close();} catch (IOException e) {e.printStackTrace();}}}

2.UDP

（1）UDPServer.java

package com.interview.javabasic.socket;import .DatagramPacket;import .DatagramSocket;public class UDPServer {public static void main(String[] args) throws Exception {// 服务端接受客户端发送的数据报//监听的端口号DatagramSocket socket = new DatagramSocket(65001);//存储从客户端接受到的内容byte[] buff = new byte[100];DatagramPacket packet = new DatagramPacket(buff, buff.length);//接受客户端发送过来的内容，并将内容封装进DatagramPacket对象中 socket.receive(packet);//从DatagramPacket对象中获取到真正存储的数据byte[] data = packet.getData();//将数据从二进制转换成字符串形式String content = new String(data, 0, packet.getLength());System.out.println(content);//将要发送给客户端的数据转换成二进制byte[] sendedContent = String.valueOf(content.length()).getBytes();// 服务端给客户端发送数据报//从DatagramPacket对象中获取到数据的来源地址与端口号DatagramPacket packetToClient = new DatagramPacket(sendedContent,sendedContent.length, packet.getAddress(), packet.getPort());//发送数据给客户端 socket.send(packetToClient);}}

（2）UDPClient.java

package com.interview.javabasic.socket;import .DatagramPacket;import .DatagramSocket;import .InetAddress;public class UDPClient {public static void main(String[] args) throws Exception {// 客户端发数据报给服务端DatagramSocket socket = new DatagramSocket();// 要发送给服务端的数据byte[] buf = "Hello World".getBytes();// 将IP地址封装成InetAddress对象InetAddress address = InetAddress.getByName("127.0.0.1");// 将要发送给服务端的数据封装成DatagramPacket对象 需要填写上ip地址与端口号DatagramPacket packet = new DatagramPacket(buf, buf.length, address,65001);// 发送数据给服务端 socket.send(packet);// 客户端接受服务端发送过来的数据报byte[] data = new byte[100];// 创建DatagramPacket对象用来存储服务端发送过来的数据DatagramPacket receivedPacket = new DatagramPacket(data, data.length);// 将接受到的数据存储到DatagramPacket对象中 socket.receive(receivedPacket);// 将服务器端发送过来的数据取出来并打印到控制台String content = new String(receivedPacket.getData(), 0,receivedPacket.getLength());System.out.println(content);}}