用comet监听两个属性，但不能正常显示

liguicheng2006 2009-09-22 11:01:26

小弟不太懂javascript,请高手不吝指教。小弟想用comet模拟监听一个属性文件中的两个属性，并分别显示在两个textArea中。但是搞不懂显示上的问题。
--------------------
显示页面如果把 http_request.responseText 都显示在两个textArea中，则没有问题；结果为
aTextArea
ran1,ran2
ran2,ran3
...
------------------
bTextArea
ran1,ran2
ran2,ran3
...
--------------------
这证明服务器端每次都发过来两个随机数，并用“，”连接成一个字符串，这是我想要的，页面代码如下：



<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>Insert title here</title>

 <script>



 function createHttpRequest() { 

		if(window.ActiveXObject){ 

			try { 

				// MSXML2 

				return new ActiveXObject("Msxml2.XMLHTTP"); 

			} catch (e) { 

				try { 

					// MSXML 

					return new ActiveXObject("Microsoft.XMLHTTP"); 

				} catch (e2) { 

					return null; 

				} 

			} 

		} else if(window.XMLHttpRequest){ 

			return new XMLHttpRequest(); 

		} else { 

			return null; 

		} 

	} 

 

 function CometEx(aText, bText) {

	 

   var http_request = createHttpRequest();

   http_request.open("GET", 'http://localhost:8080/MyComet/CometServlet', true);

   http_request.onreadystatechange = function() {

   var text,str;

   text = http_request.responseText;

   str = text.split(",");

     if (http_request.readyState == 3 && http_request.status == 200) {

          



          aText.value = text;

          bText.value = text;

          

     }

   };

   http_request.send(null);

 }

 </script>

</head>

<body>

<FORM   NAME="aForm">  

<!--   ONSELECT="storeCaret(this);"   ONCLICK="storeCaret(this);"   ONKEYUP="storeCaret(this);" -->

  <TEXTAREA   NAME="aTextArea"   ROWS="5"   COLS="80"   WRAP="soft" > value:</TEXTAREA>    

  <BR>

  <textarea name="bTextArea" rows="5" cols="80" wrap="soft"> value:</textarea>

  <BR>

  <INPUT   TYPE="button"   VALUE="Go!"   ONCLICK="CometEx(this.form.aTextArea, this.form.bTextArea);">  

</FORM> 



</body>

</html>

-----------------------------------
但是想分别显示在两个TextArea中时，总是达不到预期。
修改页面js代码为红色部分更改为：
aText.value = str[0];
bText.value = str[1];
----------------------
预期为：实则结果为：
aTextArea aTextArea
ran1 ran1
ran2 (没了)
...
------------------ ---------------------------------
bTextArea bTextArea
ran2 ran2
ran3 ran2
... (没了)
-------------------- -------------------------------
服务器端servlet代码为：



public class CometServlet extends HttpServlet implements CometProcessor{

	private static final long serialVersionUID = 1L;

	

	private String word  ;

	

    /**

     * @see HttpServlet#HttpServlet()

     */

    public CometServlet() {

        super();

        // TODO Auto-generated constructor stub

    }



    

    

	@Override

	public void init() throws ServletException {

		// TODO Auto-generated method stub

		super.init();

		word = String.valueOf(Math.random());

		System.out.println("--init-----------------");

	}







	@Override

	public void event(CometEvent e) throws IOException, ServletException {

		// TODO Auto-p method stub

		System.out.println("--event-----------------");

		if(e.getEventType() == EventType.BEGIN){

			System.out.println("--eventType BEGIN-----------------");

			HttpServletResponse response = e.getHttpServletResponse();

//			HttpServletRequest request = e.getHttpServletRequest();

			RadomNumber ran = new RadomNumber(response);

			new Thread(ran).start();

		} else if(e.getEventType() == EventType.READ){

			System.out.println("--eventType READ -----------------");

		}

	}

	

	

	private class RadomNumber implements Runnable{

		

		private ServletResponse connection;

		private boolean running = true;

		private String ran;

		

		RadomNumber(ServletResponse response){

			this.connection = response;

		}

		

		public void stop(){

			running = false;

		}



		@Override

		public void run() {

			// TODO Auto-generated method stub

			System.out.println("--RadomNumber RUN-----------------");

			

			while (running) {

				System.out.println("--RadomNumber WHILE-----------------");

				PrintWriter out = null;

				ran = String.valueOf(Math.random());

//				if (!ran.equals(word)) {

					try {

						out = connection.getWriter();

						word = word + "," + ran;

					} catch (IOException e) {

						// TODO Auto-generated catch block

						e.printStackTrace();

					}

					out.write(word);

					out.println();

					out.flush();

					try {

						Thread.sleep(5000L);

					} catch (InterruptedException e) {

						// TODO Auto-generated catch block

						e.printStackTrace();

					}

					word = ran;

//				}

			}

		}

		

	}





}