dwr为甚麽不能再不同页面同步消息，总是延时？解决思路
日期：2014-05-20 浏览次数：20680 次
dwr为甚麽不能再不同页面同步消息，总是延时？
问题是这样的
我首先打开 2个网页http://localhost/chat/test.jsp
然后再其中一个输入1在这个网页显示啦，另一个没有显示，
然后我在第二个网页输入2，然后显示 1 2
也就是把第一次的也显示啦，为甚麽我第一次的时候没有同步呢？
test.jsp
HTML code
<%@ 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>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/interface/Chat.js'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/engine.js'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/util.js'></script>
<script type='text/javascript' src='js/chat.js'></script>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>chat</title>
</head>
<body onload="init()">
<textarea readonly="readonly" rows="20" cols="30" id="content">
</textarea>
<input type="text" id="input" />
<button onclick="send()">发送</button>
</body>
</html>
chat.js
JScript code
/**
*
*/
//测试是否全为空格
init=function(){
dwr.engine.setActiveReverseAjax =true;
};
isEmpty=function(string){
return string==""||string.match(/[^\s]/)==null;
};
send=function(){
var input=dwr.util.getValue("input");
if(!isEmpty(input)){
Chat.send(input);
}
};
update=function(messageInformation){
// var last=dwr.util.getValue("content");
// dwr.util.setValue("content",last+"\n"+sendMessage);
alert(messageInformation.message);
var last=document.getElementById("content").innerHTML;
if(last!=null){
last+="\n";
}
var totalMessage=messageInformation.ip+":"+messageInformation.message+"\n"+" "+messageInformation.date;
document.getElementById("content").innerHTML=last+totalMessage;
};
Chat。java
Java code
package mychat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.directwebremoting.*;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProxy;
import org.directwebremoting.annotations.ScriptScope;
@RemoteProxy(scope=ScriptScope.APPLICATION)
public class Chat {
public Chat() {
super();
// TODO Auto-generated constructor stub
// Util.execute(this);
}
@RemoteMethod
public void send(final String sendMessage) {
// TODO Auto-generated method stub
String ip=WebContextFactory.get().getHttpServletRequest().getLocalAddr();
final MessageInformation mi=new MessageInformation(ip,sendMessage,new SimpleDateFormat("h:mm a").format(new Date()).toString());
Browser.withCurrentPage((new Runnable() {
public void run() {
System.out.println(mi);
ScriptSessions.addFunctionCall("update", mi);
}
}));
}
问题是这样的
我首先打开 2个网页http://localhost/chat/test.jsp
然后再其中一个输入1在这个网页显示啦，另一个没有显示，
然后我在第二个网页输入2，然后显示 1 2
也就是把第一次的也显示啦，为甚麽我第一次的时候没有同步呢？
test.jsp
HTML code
<%@ 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>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/interface/Chat.js'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/engine.js'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/util.js'></script>
<script type='text/javascript' src='js/chat.js'></script>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>chat</title>
</head>
<body onload="init()">
<textarea readonly="readonly" rows="20" cols="30" id="content">
</textarea>
<input type="text" id="input" />
<button onclick="send()">发送</button>
</body>
</html>
chat.js
JScript code
/**
*
*/
//测试是否全为空格
init=function(){
dwr.engine.setActiveReverseAjax =true;
};
isEmpty=function(string){
return string==""||string.match(/[^\s]/)==null;
};
send=function(){
var input=dwr.util.getValue("input");
if(!isEmpty(input)){
Chat.send(input);
}
};
update=function(messageInformation){
// var last=dwr.util.getValue("content");
// dwr.util.setValue("content",last+"\n"+sendMessage);
alert(messageInformation.message);
var last=document.getElementById("content").innerHTML;
if(last!=null){
last+="\n";
}
var totalMessage=messageInformation.ip+":"+messageInformation.message+"\n"+" "+messageInformation.date;
document.getElementById("content").innerHTML=last+totalMessage;
};
Chat。java
Java code
package mychat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.directwebremoting.*;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProxy;
import org.directwebremoting.annotations.ScriptScope;
@RemoteProxy(scope=ScriptScope.APPLICATION)
public class Chat {
public Chat() {
super();
// TODO Auto-generated constructor stub
// Util.execute(this);
}
@RemoteMethod
public void send(final String sendMessage) {
// TODO Auto-generated method stub
String ip=WebContextFactory.get().getHttpServletRequest().getLocalAddr();
final MessageInformation mi=new MessageInformation(ip,sendMessage,new SimpleDateFormat("h:mm a").format(new Date()).toString());
Browser.withCurrentPage((new Runnable() {
public void run() {
System.out.println(mi);
ScriptSessions.addFunctionCall("update", mi);
}
}));
}
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