Java Socket使用小技巧

这几天一直在写一个GPS+SMS模式的定位程序，流程大致是这样，首先接收用户的定位请求，然后把这个请求按照制定的协议用xml包装，用Socket发给短信服务器，短信服务器发送指令至终端，终端反回经续度，然后再把这个经纬度送到GIS系统，获取地理信息位置描述，最后把这个结果返回给客户端。

   但是因为网络或其它的原因，短信服务器经常没有响应，因此必须不停的建接，直到这个连接被建立。

client code

 

package com.tdt.client;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.PrintWriter;import java.net.Socket;import java.net.UnknownHostException;import java.util.Timer;import java.util.TimerTask;import javax.net.SocketFactory;public class Client {private static Client client;private static Timer timer = new Timer();private static String host="localhost";private int port =5555;private static Socket socket;private Client() throws UnknownHostException, IOException {socket = SocketFactory.getDefault().createSocket(host, port);System.out.println("connection "+host+":"+port+" success!");}//获得输出对象private PrintWriter getWriter(Socket socket) throws IOException {OutputStream socketOut = socket.getOutputStream();return new PrintWriter(socketOut,true);}//获得读取对象private BufferedReader getReader(Socket socket) throws IOException {InputStream socketIn = socket.getInputStream();return new BufferedReader(new InputStreamReader(socketIn));}//会话public void talk() throws IOException {try {BufferedReader br = getReader(socket);PrintWriter pw = getWriter(socket);BufferedReader localReader = new BufferedReader(new InputStreamReader(System.in));String msg=null;while((msg=localReader.readLine()) !=null)  {if(msg.equalsIgnoreCase("bye")) {System.out.println("会话结束");break;}pw.println(msg);System.out.println("server:"+br.readLine());}}catch(IOException e) {e.printStackTrace();}finally {try {if (socket !=null)socket.close();} catch(IOException e) {e.printStackTrace();}}}//实例化clientpublic static void instance() {if(client ==null) {try {client = new Client();} catch (Exception e) {System.err.println(e.getMessage() +":"+host);}}}public static void main(String[] args) throws Exception{if(args.length !=0) {host = args[0].toString();}//用阻塞方法或计时器不断与服务连接，直到连接被建立/*while(true) {System.out.println("开始实例化");instance();if(client !=null)break;Thread.sleep(1000 *5);} client.talk(); */timer.schedule(new TimerTask() {public void run() {if(client ==null) {instance();} else {timer.cancel();try {client.talk();} catch (IOException e) {System.err.println("IO流异常"); }}}}, 0, 1000 * 5);}}

 

server code

package com.tdt.server;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;public class Server {private ServerSocket serverSocket = null;private Socket socket = null;private int port =5555;public Server() {try {serverSocket = new ServerSocket(port);System.out.println("服务器端监听"+port+"端口");} catch (IOException e) {e.printStackTrace();}}//获取输入流读取对象public BufferedReader getReader(Socket st) throws IOException {InputStream socketIn = st.getInputStream();return new BufferedReader(new InputStreamReader(socketIn));}//获取输出对象public PrintWriter getWriter(Socket st) throws IOException{OutputStream out = st.getOutputStream();return new PrintWriter(out,true);}public String echo(String msg) {return "通讯测试，由服务器端发出";}public void service() {try {socket=serverSocket.accept();System.out.println("有客户端连接");System.out.println("IP="+socket.getInetAddress()+":"+socket.getPort());} catch (IOException e1) {e1.printStackTrace();}while(true) {try {BufferedReader br = getReader(socket);PrintWriter pw = getWriter(socket);String msg = null;while((msg =br.readLine()) !=null) {System.out.println("client:"+msg);String echoMsg = echo(msg);pw.println(echoMsg);System.out.println("服务器回应:"+echoMsg);if(msg.equalsIgnoreCase("bye")) {break;}}}catch(IOException e) {e.printStackTrace();System.out.println("IO流异常");} finally {try {if(serverSocket!=null) serverSocket.close();if(socket !=null) socket.close();System.out.println("通讯测试结束，服务器端关闭");System.exit(0);} catch(IOException e) {e.printStackTrace();}}}}public static void main(String[] args) {//启动服务器new Server().service();}}

 

先启动client，让它不停的去连服务端，当然了，服务器端没有启动肯定没法与服务器建立连接

启动服务器端