Java網路編程：TCP和UDP

TCP：

import java.net.ServerSocket;import java.net.Socket;import java.io.DataOutputStream;public class J_Server {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubtry {ServerSocket server=new ServerSocket(5000);while(true){Socket s=server.accept();System.out.println("伺服器端接收串連");DataOutputStream dataOut=new DataOutputStream(s.getOutputStream());dataOut.writeUTF("來自伺服器端的問候");dataOut.close();s.close();}} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

import java.net.Socket;import java.net.UnknownHostException;import java.io.DataInputStream;public class J_Client {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubtry {Socket s=new Socket("localhost",5000);DataInputStream dataIn=new DataInputStream(s.getInputStream());System.out.println("用戶端接收:"+dataIn.readUTF());dataIn.close();s.close();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

UDP:

import java.net.DatagramSocket;import java.net.DatagramPacket;import java.net.SocketException;import java.net.InetAddress;public class J_UdpServer {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubDatagramSocket dSocket;DatagramPacket inPacket;DatagramPacket outPacket;InetAddress cAddr;int cPort;int count=0;try {dSocket=new DatagramSocket(8000);while(true){count++;inPacket=new DatagramPacket(new byte[100],100);dSocket.receive(inPacket);//接收資料包，存入inPacketcAddr=inPacket.getAddress();cPort=inPacket.getPort();String s = new String(inPacket.getData(),0,inPacket.getData().length);System.out.println("第"+count+"台裝置接入");System.out.println("Message:"+s);System.out.println("ClientAddr:"+cAddr.getHostName());System.out.println("ClientPort:"+cPort);String outData="returnback_"+String.valueOf(count);outPacket=new DatagramPacket(outData.getBytes(),outData.getBytes().length,cAddr,cPort);dSocket.send(outPacket);}} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

import java.net.DatagramSocket;import java.net.DatagramPacket;import java.net.SocketException;import java.net.InetAddress;public class J_UdpClient {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubDatagramSocket dSocket;DatagramPacket inPacket;DatagramPacket outPacket;InetAddress sAddr;try {dSocket=new DatagramSocket();sAddr=InetAddress.getByName("localhost");String outData="請求串連...";outPacket=new DatagramPacket(outData.getBytes(),outData.getBytes().length,sAddr,8000);dSocket.send(outPacket);//發送資料包inPacket=new DatagramPacket(new byte[100],100);dSocket.receive(inPacket);//接收資料包，存入inPacketString s = new String(inPacket.getData(),0,inPacket.getData().length);System.out.println("Message:"+s);System.out.println("ServerAddr:"+inPacket.getAddress().getHostName());System.out.println("ServerPort:"+inPacket.getPort());dSocket.close();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}