Socket编程(基于web应用程序)

本文主要介绍在web应用程序下怎么使用Socket建立连接

一：首先要新建线程监听类，负责启动一个服务端线程，在web.xml中监听

说明：本来port已经在xml文件中配置，为了方便测试修改，统一放在常量类中

<context-param>        <param-name>socketPort</param-name>        <param-value>8883</param-value>    </context-param>    <listener>        <description>Socket</description>        <listener-class>com.zlxls.socket.ServerSocketListener</listener-class>    </listener>

ServerSocketListener.java

package com.zlxls.socket;import com.common.Constants;import javax.servlet.ServletContext;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;/** * ServerSocket线程监听类，负责启动一个服务端线程 * @ClassNmae：ServerSocketListener    * @author zlx-雄雄 * @date    2017-11-13 13:27:21 *  */public class ServerSocketListener implements ServletContextListener{        private ServerSocketThread socketThread;        @Override    public void contextDestroyed(ServletContextEvent e){                if (socketThread != null && socketThread.isInterrupted()){                        socketThread.closeServerSocket();                        socketThread.interrupt();                    }    }    @Override    public void contextInitialized(ServletContextEvent e){                ServletContext servletContext = e.getServletContext();                System.out.println("Socket 服务端初始化完成：Server contextInitialized over");                if (socketThread == null){                        socketThread = new ServerSocketThread(Constants.port);// 从web.xml中context-param节点获取socket端口                        socketThread.start();                     }    }}

二：首先本文定义相关常量：Constants.java

package com.common;import java.net.Socket;import java.util.ArrayList;import java.util.List;/** *  * 系统常量定义类-全局变量 * @ClassNmae：Constants * @author zlx-雄雄 * @date    2017-8-16 11:42:41 *  */public class Constants {    /**     * Socket相关     */    public static final String  over = "over";        public static final int  port = 8123;        public static final String  encode = "gb2312";        public static  int socketCount = 0;        public static List<Socket> socketList = new ArrayList<>();}

三：服务端启动客户端线程操作类ServerSocketThread.java

package com.zlxls.socket;import com.common.Constants;import com.zlxls.util.DateUtil;import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;/** * 服务端启动客户端线程操作类 * 负责接收客户端请求，并启动一个线程为此请求服务 * @ClassNmae：ServerSocketThread    * @author zlx-雄雄 * @date    2017-11-13 13:28:01 *  */public class ServerSocketThread extends Thread{            private ServerSocket serverSocket;    public ServerSocketThread(int port){                if (serverSocket == null){                        try{                                this.serverSocket = new ServerSocket(port);                            }catch (IOException e){                                e.printStackTrace();                            }        }    }        @Override    public void run(){        try{            while (!this.isInterrupted()){//this.isInterrupted()方法用来检测“this”的中断状态，且不会改变线程的状态标志。                                Socket socket = serverSocket.accept();                                                System.out.println("服务线程数量：Server SocketThread start:"+(++Constants.socketCount));                                if (socket != null){                                        Constants.socketList.add(socket);                                        System.out.println("新的Socket连接：new commer:"+socket.getLocalAddress()+":"+socket.getLocalPort()+"--"+socket.getInetAddress().getHostName()+":"+socket.getRemoteSocketAddress().toString()+"--"+DateUtil.getTime());                                        ServerSocketReceiveThread serverSocketReceiveThread = new ServerSocketReceiveThread(socket);                                        serverSocketReceiveThread.start();                                    }            }        }catch (Exception ex){                        System.out.println("SocketThread err:"+ex.getMessage());                    }    }        public void closeServerSocket(){        try{            if (serverSocket != null && !serverSocket.isClosed()){                                serverSocket.close();                            }            System.out.println("SocketThread close");                    }catch (Exception ex){                        System.out.println("SocketThread err:"+ex.getMessage());                    }    }}

四：服务端消息处理线程ServerSocketReceiveThread.java

package com.zlxls.socket;import com.common.Constants;import com.zlxls.util.DateUtil;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.Socket;import com.alibaba.fastjson.JSONObject;/** * 服务端消息处理线程 * 包括接收客户端消息，并且返回消息给客户端 * 将消息解析为json，用作处理 * @ClassNmae：ServerSocketReceiveThread    * @author zlx-雄雄 * @date    2017-11-13 16:58:38 *  */public class ServerSocketReceiveThread extends Thread{        private final Socket socket;        public ServerSocketReceiveThread(Socket socket){                  this.socket = socket;              }           @Override    public void run(){        BufferedReader bufferedReader = null;        PrintWriter printWriter = null;                        try{            //获取客户端传入信息            bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream(),Constants.encode));            //得到客户端输出流            printWriter = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Constants.encode));                        int count = 0;            while (true){                                String cmdmsg = bufferedReader.readLine();                                //如果为空，表示当前连接已经关闭，客户端即是是空字符串，这里也不会为null                if(cmdmsg==null) {                                        System.out.println("已关闭--新的Socket连接：new commer:"+socket.getLocalAddress()+":"+socket.getLocalPort()+"--"+socket.getInetAddress().getHostName()+":"+socket.getRemoteSocketAddress().toString()+"--"+DateUtil.getTime());                                        Constants.socketCount--;                                        Constants.socketList.remove(socket);                                        break;                }                /**                 * 将消息解析为json进行处理                 * ...                 */                                String time  = DateUtil.getTime();                //打印客户端信息                System.out.println(time+"：服务接收：Server received:现在是与"+socket.getRemoteSocketAddress().toString()+"第["+(++count)+"]次会话--消息内容:【" + cmdmsg+"】");                //将信息返回给客服端                printWriter.println(socket.getRemoteSocketAddress().toString()+"你好,现在是第["+count+"]次会话--"+time+"，服务端已经收到你的消息:【"+cmdmsg+"】");                printWriter.flush();                /**                 * 这个在服务端其实没有作用                 * 前端请求连接关闭后，传回来的消息是null，因此只要判断消息为null,就可以说明客户端已经关闭了连接                 */                if (cmdmsg.equals(Constants.over)) break;                           }                        bufferedReader.close();            printWriter.close();            socket.close();                    }catch (IOException ex){            ex.printStackTrace();        }    }}

五：客户端SocketClient.java

package com.zlxls.socket;import com.common.Constants;import com.zlxls.util.DateUtil;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.Socket;/** * SocketClient客户端，负责发送请求和消息 * @ClassNmae：SocketClient    * @author zlx-雄雄 * @date    2017-11-11 9:55:39 *  */public class SocketClient {        public static void main(String args[]) {                 Socket socket;                        PrintWriter printWriter;                BufferedReader bufferedReader;                BufferedReader bufferedReaderFromServer;                try{              socket=new Socket("127.0.0.1",Constants.port);                          String str="请输入消息内容:";                        System.out.print(str);              //获取输入流            bufferedReader=new BufferedReader(new InputStreamReader(System.in, Constants.encode));              //读取输入信息                          String readline=bufferedReader.readLine();              //获取输出流，将信息输出到服务端            printWriter=new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Constants.encode));              //获取输入流，取得服务端返回信息            bufferedReaderFromServer = new BufferedReader(new InputStreamReader(socket.getInputStream(),Constants.encode));                          while(!readline.equals(Constants.over)){                  //将输入流获取信息发送给服务端                printWriter.println(readline);                                                  printWriter.flush();                  //输出输入流信息                System.out.println(DateUtil.getTime()+"--Client:"+readline);                  //输出服务端返回信息                System.out.println(DateUtil.getTime()+"--Server:"+bufferedReaderFromServer.readLine());                  //循环读取                System.out.print(str);                                  readline=bufferedReader.readLine();              }                          printWriter.close();                          bufferedReader.close();                        bufferedReaderFromServer.close();                        socket.close();                      }catch(IOException e) {                          e.printStackTrace();        }    }  }