tomcat+comet兑现终端与服务端同步的小例子

tomcat+comet实现终端与服务端同步的小例子
1、工程说明
java project——CometSocket包含一个类：
Calculate.java：作为客户端，往服务器发送数据

web project——CometServer包含：
ReceiverServlet.java：接收客户端数据，并模拟入库（以存入文件的形式）
TestServlet.java：模拟从库中取数据（从文件中取值）并推送给浏览器展示
index.jsp：接收从服务端推送出来的数据并展示

2、部分代码说明
Calculate.java

 public void sendData(ActionEvent e)    {              try    {            //发送数据            txtResult.setText(e.getActionCommand());            URL url = new URL("http://localhost:8080/CometServer/rs?num="+txtResult.getText());            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();            httpURLConnection.setRequestProperty("Content-Type", "text/html"); //application/xml            httpURLConnection.setRequestMethod("GET");            httpURLConnection.setReadTimeout(2*1000);            int code = httpURLConnection.getResponseCode();            System.out.println("code_______________"+code);    }

通过http get请求方式将数据发送给客户端

ReceiverServlet.java

public void service(HttpServletRequest request ,HttpServletResponse response){        FileOutputStream fos = null;        try        {            String str = request.getParameter("num");            System.out.println("get________________________________"+str);            File file = new File("D:/1.txt");            fos = new FileOutputStream(file);            if(str != null){                fos.write(str.getBytes());            }                    }        catch (FileNotFoundException e)        {            // TODO Auto-generated catch block            e.printStackTrace();        }        catch (IOException e)        {            // TODO Auto-generated catch block            e.printStackTrace();        }finally{            if(fos != null){                try                {                    fos.close();                }                catch (IOException e)                {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }                    }    }

接收数据并模拟入库

TestServlet.java

public void event(CometEvent event) throws IOException, ServletException    {        // 开始        if(event.getEventType() == EventType.BEGIN){            try            {                Thread.sleep(100);                    File file = new File ("D:/1.txt");                BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));                String str = br.readLine();                System.out.println("ddd1_________"+str);                  if( str != null){                    HttpServletResponse response = event.getHttpServletResponse();                    PrintWriter out = response.getWriter();                    out.write(str);                    out.flush();                      out.close();                }            }            catch (Exception e)            {                // TODO Auto-generated catch block                e.printStackTrace();            }                      }        if(event.getEventType() == EventType.END){            System.out.println("ddd2");            event.close();        }                    }

定时向服务器推送数据

3、运行
tomcat配置：要使用 Comet，需要对 Tomcat 的配置文件 server.xml 稍作修改。默认情况下启用的是更典型的同步 IO 连接器。现在只需将它切换成异步版本.

<Connector connectionTimeout="20000" port="8080" protocol="org.apache.
coyote.http11.Http11NioProtocol" redirectPort="8443"/>

源码和效果图，如附件：

启动web工程，点击“start”
运行Calculate.java

tomcat+comet兑现终端与服务端同步的小

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