基于DWR推技術留言板
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.ScriptSession;
import org.directwebremoting.WebContext;
import org.directwebremoting.WebContextFactory;
import org.directwebremoting.util.Logger;
/**
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class JavascriptChat
{
/**
* @param text The new message text to add
*/
public void addMessage(String text)
{
if (text != null && text.trim().length() > 0)
{
messages.addFirst(new Message(text));
while (messages.size() > 10)
{
messages.removeLast();
}
}
WebContext wctx = WebContextFactory.get();
String currentPage = wctx.getCurrentPage();
ScriptBuffer script = new ScriptBuffer();
script.appendScript("receiveMessages(")
.appendData(messages)
.appendScript(");");
// Loop over all the users on the current page
Collection pages = wctx.getScriptSessionsByPage(currentPage);
for (Iterator it = pages.iterator(); it.hasNext();)
{
ScriptSession otherSession = (ScriptSession) it.next();
otherSession.addScript(script);
}
}
/**
* The current set of messages
*/
private LinkedList messages = new LinkedList();
/**
* The log stream
*/
protected static final Logger log = Logger.getLogger(JavascriptChat.class);
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Simple DWR Chat Version 2.0</title>
<script type='text/javascript' src='../dwr/engine.js'> </script>
<script type='text/javascript' src='../dwr/interface/JavascriptChat.js'> </script>
<script type='text/javascript' src='../dwr/util.js'> </script>
<script type="text/javascript" src='javascript-chat.js'> </script>
<link rel="stylesheet" type="text/css" href="../generic.css" />
</head>
<body onload="init()">
<div id="page-title">[
<a href="http://getahead.org/dwr/">DWR Website</a> |
<a href="..">Web Application Index</a>
]</div>
<h1>Javascript Chat</h1>
<p>This is a very simple chat demo that uses reverse ajax to collect messages
and Javascript to manipulate the pages with the results.</p>
<p>
Your Message:
<input id="text" onkeypress="dwr.util.onReturn(event, sendMessage)"/>
<input type="button" value="Send" onclick="sendMessage()"/>
</p>
<hr/>
<div id="chatlog"></div>
</body>
</html>
function init() {
dwr.engine.setActiveReverseAjax(true);
}
function sendMessage() {
var text = dwr.util.getValue("text");
dwr.util.setValue("text", "");
JavascriptChat.addMessage(text);
}
function receiveMessages(messages) {
var chatlog = "";
for (var data in messages) {
chatlog = "<div>" + dwr.util.escapeHtml(messages[data].text) + "</div>" + chatlog;
}
dwr.util.setValue("chatlog", chatlog, { escapeHtml:false });
}
import java.util.Iterator;
import java.util.LinkedList;
import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.ScriptSession;
import org.directwebremoting.WebContext;
import org.directwebremoting.WebContextFactory;
import org.directwebremoting.util.Logger;
/**
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class JavascriptChat
{
/**
* @param text The new message text to add
*/
public void addMessage(String text)
{
if (text != null && text.trim().length() > 0)
{
messages.addFirst(new Message(text));
while (messages.size() > 10)
{
messages.removeLast();
}
}
WebContext wctx = WebContextFactory.get();
String currentPage = wctx.getCurrentPage();
ScriptBuffer script = new ScriptBuffer();
script.appendScript("receiveMessages(")
.appendData(messages)
.appendScript(");");
// Loop over all the users on the current page
Collection pages = wctx.getScriptSessionsByPage(currentPage);
for (Iterator it = pages.iterator(); it.hasNext();)
{
ScriptSession otherSession = (ScriptSession) it.next();
otherSession.addScript(script);
}
}
/**
* The current set of messages
*/
private LinkedList messages = new LinkedList();
/**
* The log stream
*/
protected static final Logger log = Logger.getLogger(JavascriptChat.class);
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Simple DWR Chat Version 2.0</title>
<script type='text/javascript' src='../dwr/engine.js'> </script>
<script type='text/javascript' src='../dwr/interface/JavascriptChat.js'> </script>
<script type='text/javascript' src='../dwr/util.js'> </script>
<script type="text/javascript" src='javascript-chat.js'> </script>
<link rel="stylesheet" type="text/css" href="../generic.css" />
</head>
<body onload="init()">
<div id="page-title">[
<a href="http://getahead.org/dwr/">DWR Website</a> |
<a href="..">Web Application Index</a>
]</div>
<h1>Javascript Chat</h1>
<p>This is a very simple chat demo that uses reverse ajax to collect messages
and Javascript to manipulate the pages with the results.</p>
<p>
Your Message:
<input id="text" onkeypress="dwr.util.onReturn(event, sendMessage)"/>
<input type="button" value="Send" onclick="sendMessage()"/>
</p>
<hr/>
<div id="chatlog"></div>
</body>
</html>
function init() {
dwr.engine.setActiveReverseAjax(true);
}
function sendMessage() {
var text = dwr.util.getValue("text");
dwr.util.setValue("text", "");
JavascriptChat.addMessage(text);
}
function receiveMessages(messages) {
var chatlog = "";
for (var data in messages) {
chatlog = "<div>" + dwr.util.escapeHtml(messages[data].text) + "</div>" + chatlog;
}
dwr.util.setValue("chatlog", chatlog, { escapeHtml:false });
}