dwr spring整合

Ajax,它使瀏覽器可以爲用戶提供更爲自然的瀏覽體驗,對於j2EE WEB開發人員來說,使用DWR框架可以很簡單的使用Ajax技術.
本文以一個DWR+SPRING的實例來說明DWR的使用
1、將dwr.jar放到應用的/WEB-INF/lib目錄下
2、配置web.xml,增加如下代碼:

代碼

<!--初始化WebApplicationContext-->  
 <context-param>  
        <param-name>contextConfigLocation</param-name>  
        <param-value>/WEB-INF/applicationContext.xml,/WEB-INF/action-servlet.xml</param-value>  
 </context-param>  
 <listener>  
       <listener-class>  
             org.springframework.web.context.ContextLoaderListener   
       </listener-class>  
 </listener>  
<!--配置DWR攔截器-->  
 <servlet>  
  <servlet-name>dwr-invoker</servlet-name>  
  <servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>  
  <init-param>  
   <param-name>debug</param-name>  
   <param-value>true</param-value>  
  </init-param>  
 </servlet>  
 <servlet-mapping>  
  <servlet-name>dwr-invoker</servlet-name>  
  <url-pattern>/dwr/*</url-pattern>  
 </servlet-mapping>  

3、增中dwr.xml文件
文件內容：
代碼

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN" "http://www.getahead.ltd.uk/dwr/dwr10.dtd">  
<dwr>  
 <allow>  
  <create creator="spring" javascript="DWRUser">  
   <param name="beanName" value="DWRUser"/>  
  </create>  
 </allow>  
</dwr>  

creator屬性的值可以是new,struts,spring......因爲此處是整合spring來做的，所以設置成“spring”，javascript="DWRUser" 表示實例轉換成javascript語言後以DWRUser命名，前臺頁面可以通過代碼（<script type='text/javascript' src='../../dwr/interface/DWRUser.js'></script>）來調用。param元素的name屬性值可以是class,beanName等，此處用beanName,value得值是定義在applicationContext.xml中某個bean的id值。
4、創建一個實體bean供DWR轉換成js
代碼

package com.note.dwr;   
import com.note.bussies.service.IUserService;   
public class User {   
 private IUserService ius;   

 public IUserService getIus() {   
  return ius;   
 }   
 public void setIus(IUserService ius) {   
  this.ius = ius;   
 }   
 public User(){   

 }   
 public boolean isExist(String username) {   
      Users user = this.ius.getUserByName(username);   
      return (null == user) ? false : true;   
 }   
} 

5、在applicationContext.xml中配置第4步寫的bean
代碼
......

<bean id="DWRUser" class="com.note.dwr.User">  
  <property name="ius">  
   <ref bean="UserService" />  
  </property>  
 </bean>  

......

6、在視圖頁面中調用
先導入以下文，每個文件的功能這裏不再詳述
代碼

<script type='text/javascript' src='../../dwr/interface/DWRUser.js'></script>  
<script type='text/javascript' src='../../dwr/engine.js'></script>  
<script type='text/javascript' src='../../dwr/util.js'></script>  

因爲我的視圖文件是放在/view/user/下，所以這裏用了../../返回到根
具體調用：
代碼

<script type='text/javascript'>  
 function regUserChked(){   
  var username=$("username").value;   
  DWRUser.isExist(username,showData);//showData回調函數   
 }   
 function showData(data){   
     if(data){   
          DWRUtil.setValue("userMsg","該用戶名已經被註冊，請更換您的用戶名！");   
     }else{   
          DWRUtil.setValue("userMsg","恭喜您，該用戶名尚未被註冊！");         
     }   
 }   
</script>  
input type="text" name="username" value="" οnblur="regUserChked()" /><div id="userMsg"></div>