DWR Reverse Ajax

1. Class

 

1.1 handle class

 

Package com. cloverworxs. uma. helper; <br/> import java. util. collection; <br/> import java. util. export list; <br/> import org. directwebremoting. webContext; <br/> import org. directwebremoting. webContextFactory; <br/> import org. directwebremoting. proxy. dwr. util; <br/> public class DWRHelper {</p> <p> private static final sorted list messages = new sorted list (); </p> <p> public static void addMessage (String text ){ </P> <p> if (text! = Null & text. trim (). length ()> 0) {<br/> messages. addFirst (new Message (text); <br/> while (messages. size ()> 5) {<br/> messages. removeLast (); <br/>}< br/> // Reverse Ajax code to be added here shortly <br/> WebContext wctx = WebContextFactory. get (); <br/> String currentPage = wctx. getCurrentPage (); </p> <p> // Clear the input box in the browser that kicked off this page only <br/> Util utilThis = new Util (wctx. getScriptSession (); <br/> utilThis. setValue ("text", ""); <br/> // For all the browsers on the current page: <br/> Collection sessions = wctx. getScriptSessionsByPage (currentPage); <br/> Util utilAll = new Util (sessions ); <br/> // Clear the list and add in the new set of messages <br/> utilAll. removeAllOptions ("chatlog"); <br/> utilAll. addOptions ("chatlog", messages, "text"); <br/> utilAll. addFunctionCall ("changeStyle"); <br/>}</p> <p >}< br/>

 

1.2 Bean class

Package com. cloverworxs. uma. helper; <br/> import org. directwebremoting. security; <br/> public class Message {<br/> public Message (String newtext) {<br/> text = newtext; <br/> if (text. length () & gt; 256) {<br/> text = text. substring (0,256); <br/>}< br/> text = Security. replaceXmlCharacters (text); <br/>}< br/> public long getId () {<br/> return id; <br/>}< br/> public String getText () {<br/> return text; <br/>}< br/> private long id = System. currentTimeMillis (); <br/> private String text; <br/>}< br/>

 

2. Web. xml

 

<? Xml version = "1.0" encoding = "ISO-8859-1"?> <Br/> <! DOCTYPE web-app PUBLIC "-// Sun Microsystems, Inc. // DTD Web Application 2.3 // "http://java.sun.com/dtd/web-app_2_3.dtd"> <br/> <web-app> <br/> <display-name> Ajax Upload </display-name> <br/> <servlet> <br/> <servlet-name> dwr-invoker </servlet-name> <br/> <display-name> DWR Servlet </display- name> <br/> <servlet-class> uk. ltd. getahead. dwr. DWRServlet </servlet-class> <br/> <init-param> <br/> <param-name> d Ebug </param-name> <br/> <param-value> false </param-value> <br/> </init-param> <br/> <init- param> <br/> <param-name> logLevel </param-name> <br/> <param-value> WARN </param-value> <br/> </ init-param> <br/> <! -- ActiveReverseAjaxEnabled important --> <br/> <init-param> <br/> <param-name> activeReverseAjaxEnabled </param-name> <br/> <param-value> true </param-value> <br/> </init-param> <br/> <load-on-startup> 1 </load-on-startup> <br/> </servlet> <br/> <servlet-mapping> <br/> <servlet-name> dwr-invoker </servlet-name> <br/> <url-pattern> /dwr/* </url-pattern> <br/> </servlet-mapping> <br/> <! -- The Usual Welcome File List --> <br/> <welcome-file-list> <br/> <welcome-file> index. jsp </welcome-file> <br/> </welcome-file-list> <br/> </web-app> <br/>

3. DWR. xml

 

<Dwr> <br/> <allow> </p> <create creator = "none" javascript = "DWRHelper"> <br/> <param name = "class "value =" com. cloverworxs. uma. helper. DWRHelper "/> <br/> <include method =" addMessage "/> <br/> </create> </p> <convert converter =" bean "match = "com. cloverworxs. uma. helper. message "> <br/> <param name =" include "value =" id, text "/> <br/> </convert> </p> </allow> <br/> </dwr> <br/>

 

4. index. jsp

<% @ Page language = "java" contentType = "text/html; charset = UTF-8" <br/> pageEncoding = "UTF-8" %> <br/> <! DOCTYPE html PUBLIC "-// W3C // dtd html 4.01 Transitional // EN" "http://www.w3.org/TR/html4/loose.dtd"> <br/> <ptml> <br/> <pead> <br/> <meta http-equiv = "Content-Type" content = "text/html; charset = UTF-8 "> <br/> <title> Insert title here </title> <br/> <mce: script type = 'text/javascript 'src = "dwr/interface/DWRHelper. js "mce_src =" dwr/interface/DWRHelper. js "> </mce: script> <br/> <mce: script type = 'text/javascript's Rc = "dwr/engine. js "mce_src =" dwr/engine. js "> </mce: script> <br/> <mce: script type = 'text/javascript 'src =" dwr/util. js "mce_src =" dwr/util. js "> </mce: script> <br/> <mce: script type =" text/javascript "> <! -- <Br/> function sendMessage () {</p> <p> DWRHelper. addMessage (dwr. util. getValue ("text"); </p> <p >}</p> <p> function changeStyle () {</p> <p> if ($ ('chatlog '). style. listStyleType = 'decimal') {<br/> $ ('chatlog '). style. listStyleType = 'Upper-alpha'; <br/>}else {<br/> $ ('chatlog '). style. listStyleType = 'decimal'; <br/>}</p> <p >}< br/> // --> </mce: script> <br/> </pead> <br/> <! -- Dwr. engine. setActiveReverseAjax (true) important --> <br/> <body onload = "dwr. engine. setActiveReverseAjax (true ); "> <br/> <p> This is a very simple chat demo that uses reverse ajax to collect messages and server-side browser manipulation to update the pages with the results. </p> <br/> <p> Your Message: <input id = "text" onkeypress = "dwr. util. onReturn (event, sendMessage) "/> <input type =" button "value =" Send "onclick =" sendMessage () "/> </p> <br/> <pr/> <br/> <ul id =" chatlog "style =" list-style-type: armenian; "mce_style =" list-style-type: armenian; "> <br/> </ul> <br/> </body> <br/> </ptml>

 

5. Use reverse Ajax from non-DWR servlet threads

 

List containers = containerutil. getallpublishedcontainers (getservletcontext (); <br/> defaultiner iner Container = (defaultcontainer) containers. get (0); <br/> scriptsessionmanager sessionmanager = (scriptsessionmanager) container. getbean (scriptsessionmanager. class. getname (); <br/> // group <br/> // collection sessions = sessionmanager. getscriptsessionsbypage (request. getcontextpath () + file. separator + "JSP/I Mport/import. jsp "); </P> <p> // single shot. The page is displayed using a method similar to uploadform. Action =" <% = strcontextpath %>/servlet/fileupload? Scriptsessionid = "+ DWR. engine. send the scriptsessionid parameter in the form of _ getscriptsessionid () <br/> string id = (string) request. getparameter ("scriptsessionid"); <br/> realscriptsession mysession = sessionmanager. getscriptsession (ID); <br/> sessionmanager. setpageforscriptsession (mysession, request. getcontextpath () + file. separator + "JSP/import. JSP ");

 

6. Notes

 

6.1 The required class library DWR. Jar commons-logging-1.1.1.jar log4j-1.2.8.jar

6.2 log4j configuration file

 

# -------------------------------- <Br/> # level = fatalerrorwarninfodebug <br/> log4j. rootlogger = info, stdout, fileout </P> <p> log4j. appender. stdout = org. apache. log4j. leleappender </P> <p> log4j. appender. fileout = org. apache. log4j. rollingfileappender <br/> log4j. appender. fileout. file =/home/Guo/ibatis. log <br/> log4j. appender. fileout. maxfilesize = 0000kb </P> <p> log4j. appender. stdout. layout = org. apache. log4j. patternlayout <br/> log4j. appender. stdout. layout. conversionpattern = [%-5 p] % d {yyyy-mm-dd hh: mm: SS }:% M % n <br/> log4j. appender. fileout. layout = org. apache. log4j. patternlayout <br/> log4j. appender. fileout. layout. conversionpattern = [%-5 p] _ % d {yyyy-mm-dd hh: mm: SS }:% M % n </P> <p>

6.3 The DWR. xml file must start with the following content (note the version number)

 

<! Doctype DWR Public <br/> "-// getahead limited // DTD direct Web remoting 3.0 // en" <br/> "http://getahead.org/dwr/dwr30.dtd">

 

6.4 msxml5.0.dll problems are recommended to be upgraded to 3.0.