很多时候在javaweb项目中我们需要用到Socket通信来实现功能，在web中使用Socket我们需要建立一个监听程序，在程序启动时，启动socket监听。我们的应用场景是在java项目中，需要外接如一个硬件设备，通过tcp通信，获取设备传上来的数据，并对数据做回应。 先看一下web的监听代码：

import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener; public class AttendSocetListener  implements ServletContextListener{    private SocketThread socketThread;    public void contextDestroyed(ServletContextEvent arg0) {          if(null!=socketThread && !socketThread.isInterrupted())             {              socketThread.closeSocketServer();              socketThread.interrupt();             }      }         @Override      public void contextInitialized(ServletContextEvent arg0) {          // TODO Auto-generated method stub          if(null==socketThread)          {           //新建线程类           socketThread=new SocketThread(null);           //启动线程           socketThread.start();          }      }      }

创建线程：

import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;import java.util.ArrayList;import java.util.List;  public class SocketThread extends Thread{       private ServerSocket serverSocket = null;                     public SocketThread(ServerSocket serverScoket){              try {                  if(null == serverSocket){                      this.serverSocket = new ServerSocket(8877);                      System.out.println("socket start");                  }              } catch (Exception e) {                  System.out.println("SocketThread创建socket服务出错");                  e.printStackTrace();              }                 }                     public void run(){              while(true){                  try {                      if(serverSocket==null){                        break;                    }else if(serverSocket.isClosed()){                        break;                    }                    Socket socket = serverSocket.accept();                      if(null != socket && !socket.isClosed()){                             //处理接受的数据                          Thread t1 = new Thread(new SocketOperate(socket));                          t1.start();                      }else{                        break;                    }                }catch (Exception e) {                      System.out.println("SocketThread创建socket服务出错111111111111111111111111");                      e.printStackTrace();                                       }              }          }                     public void closeSocketServer(){             try {                  if(null!=serverSocket && !serverSocket.isClosed())                  {                   serverSocket.close();                  }             } catch (IOException e) {              // TODO Auto-generated catch block              e.printStackTrace();             }           }                 }

处理接受到的数据：

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.Socket; public class SocketOperate implements Runnable {       private Socket socket;       //该线程所处理的Socket所对应的输入流       BufferedReader br = null;       String str = null;       String content = null;       InputStreamReader reader=null;       public SocketOperate(Socket socket) throws IOException       {           this.socket = socket;           reader = new InputStreamReader(this.socket.getInputStream(),"utf-8");           br = new BufferedReader(reader);       }           @Override       public void run()       {           try           {               // 采用循环不断从Socket中读取客户端发送过来的数据              while (true)               {                 content = readFromClient();                 System.out.println(content);            if (content == null)               {                break;               }               OutputStream os = socket.getOutputStream();               os.write(("RES, OK,<1年2班,小明>, 123241,#" + "\n").getBytes("utf-8"));               os.flush();             }           }           catch (IOException e)           {            e.printStackTrace();           }       }       //定义读取客户端数据的方法       private String readFromClient()       {           try           {            str = br.readLine();            return str;                       }           //如果捕捉到异常，表明该Socket对应的客户端已经关闭           catch (IOException e)           {           try {             br.close();         reader.close();            socket.close();         } catch (IOException e1) {             // TODO Auto-generated catch block             e1.printStackTrace();            }          }           return null;       }   }

客户端代码：

packageimport java.io.*;import java.net.*; public class TalkClient {     public static void main(String args[]) throws UnknownHostException, IOException {         Socket socket=new Socket("192.168.3.104",8877);         PrintWriter os=new PrintWriter(socket.getOutputStream());         BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));         int i=1;         while(socket.isConnected()){         os.print("BEAT,12345678,160314,092832,1.00,123241,#"+"\n");         os.flush();         System.out.println("Client:"+i);         System.out.println("Server:"+is.readLine());         i++;         }          //继续循环         os.close(); //关闭Socket输出流         is.close(); //关闭Socket输入流         socket.close(); //关闭Socket                         }}