dwr spring整合

Ajax,它使浏览器可以为用户提供更为自然的浏览体验,对于j2EE WEB开发人员来说,使用DWR框架可以很简单的使用Ajax技术.
本文以一个DWR+SPRING的实例来说明DWR的使用
1、将dwr.jar放到应用的/WEB-INF/lib目录下
2、配置web.xml,增加如下代码:

<!--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拦截器-->
 
<
servlet
>
  
<
servlet-name
>
dwr-invoker
</
servlet-name
>
<!-- 
指定DWR核心Servlet的实现类 

-->
  
<
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
文件内容：

<?
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属性的值可以是new,struts,spring......因为此处是整合spring来做的，所以设置成 “spring”，javascript="DWRUser" 表示实例转换成javascript语言后以DWRUser命名，前台页面可以通过代码（<script src="../../dwr/interface/DWRUser.js" type="text/javascript"></script>）来调用。param元素的name属性值可以是 class,beanName等，此处用beanName,value得值是定义在applicationContext.xml中某个bean的id 值。
4、创建一个实体bean供DWR转换成js

 

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步写的bean

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

6、在视图页面中调用
先导入以下文，每个文件的功能这里不再详述

<
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
>

因为我的视图文件是放在/view/user/下，所以这里用了../../返回到根
具体调用：

<
script
 
type
=
'text/javascript'
>
  





 
function 
regUserChked(){
  var 
username
=$("username").value;
  DWRUser.isExist(username,showData);//showData回调函数
 }
 function showData(data){
     if(data){
          DWRUtil.setValue("userMsg","该用户名已经被注册，请更换您的用户名！");
     }else{
          DWRUtil.setValue("userMsg","恭喜您，该用户名尚未被注册！");
     }
 }
</
script
>
input 
type
=
"text"
 
name
=
"username"
 
value
=
""
 
onblur
=
"regUserChked()"
 
/>
<
div
 
id
=
"userMsg"
>
</
div
>