轉:
http://www.javaeye.com/topic/232685
Ajax,它使瀏覽器可以為用戶提供更為自然的瀏覽體驗,對于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:
<!--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：
<?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......因為此處是
整合spring來做的，所以設置成“
spring”，javascript="
DWRUser" 表示實例轉換成javascript語言后以
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
<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，每個文件的功能這里不再詳述
<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>
因為我的視圖文件是放在/view/user/下，所以這里用了../../返回到根
具體調用：
<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","該用戶名已經被注冊，請更換您的用戶名！");
}else{
DWRUtil.setValue("userMsg","恭喜您，該用戶名尚未被注冊！");
}
}
</script>
input type="text" name="username" value="" onblur="regUserChked()" /><div id="userMsg"></div>