让Dwr和Spring-MVC通过Annotation方式共同工作

SPRING2.X后引入了@Controller的方式标注Controller，大大简化了原来的XML方式的MVC配置，不过传统的DWR配置方式，虽然可以通过SpringCreator的方式将BEAN暴露给AJAX使用，但是仍然逃不出繁杂的XML配置，通过SPRING的annotation方式，可以简化DWR和SPRING之间的配置.

web.xml

<!-- Spring -->
	<servlet>
		<servlet-name>spring</servlet-name>
		<servlet-class>
			org.springframework.web.servlet.DispatcherServlet
		</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>
				classpath:spring/webControllerContext.xml
			</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>spring</servlet-name>
		<url-pattern>*.htm</url-pattern>
	</servlet-mapping>
	<servlet-mapping>
		<servlet-name>spring</servlet-name>
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>

将DispatcherServlet配置成管理htm和dwr

webControllerContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:dwr="http://www.directwebremoting.org/schema/spring-dwr"
	xmlns:dwra="http://www.directwebremoting.org/schema/spring-dwr-annotations"
	xsi:schemaLocation="
			http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
			http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
			http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd
			http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
			http://www.directwebremoting.org/schema/spring-dwr
            http://www.directwebremoting.org/schema/spring-dwr-2.0.xsd
            http://www.directwebremoting.org/schema/spring-dwr-annotations
            http://www.directwebremoting.org/schema/spring-dwr-annotations.xsd">
	
	<context:annotation-config/>
	
	<context:component-scan base-package="mvc" />

	<bean
		class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />

	<!-- 
		<bean
		class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
	-->

	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver"
		p:prefix="" p:suffix=".jsp" />

	<!-- DWR -->
	<dwr:configuration>
		<dwr:convert class="mvc.User" type="bean" />
		<dwr:signatures>
			<![CDATA[
				import java.util.Map;
				]]>
		</dwr:signatures>
	</dwr:configuration>

	<dwr:controller id="dwrController" debug="true" />

	<!--  New DWR capabilities-->
	<dwra:url-mapping />
	<dwra:annotation-config />
</beans>

@Controller("helloController")
@RequestMapping("/helloController.htm")
@RemoteProxy(creator = SpringCreator.class, creatorParams = @Param(name = "beanName", value = "helloController"), name = "dwrHelloController")
public class Hello {
	/**
	 * User Dao
	 */
	private UserDao userDao;

	/**
	 * Employee dao
	 */
	private EmployeeDao employeeDao;

	@RemoteMethod
	@RequestMapping
	public String sayHello() {
		String str = "hello";
		System.out.println(str);
		return str;
	}

	@RemoteMethod
	public User getUser() {
		User user = this.getUserDao().getUser();
		user.setName(user.getName() + " _ "
				+ this.getEmployeeDao().getEmployeeName());
		return user;
	}

	@RequestMapping(params = "method=sayBye")
	public ModelAndView sayBye() {
		String str = "bye";
		System.out.println(str);
		return null;
	}

	//...忽略set和get
}

可以看到，首先通过：

@Controller("helloController")
@RequestMapping("/helloController.htm")

将POJO暴露成一个SpringMvc的Controller，然后在DI给DWR，成为一个AJAX服务：

@RemoteProxy(creator = SpringCreator.class, creatorParams = @Param(name = "beanName", value = "helloController"), name = "dwrHelloController")

在指定的方法上面标注：

@RemoteMethod
@RequestMapping(params = "method=sayHello")
public String sayHello() {...}

这样，这个方法既可以成为一个controller资源，也可以被DWR访问，如：
http://localhost/mvc/helloController.htm?method=sayHello
或者在页面中用JS访问：

dwrHelloController.sayHello(function callbackFun(data){
   			alert(data);});

一举多得，实现代码的最小量

需要注意的地方：
spring的XML配置中：

http://www.directwebremoting.org/schema/spring-dwr-annotations
http://www.directwebremoting.org/schema/spring-dwr-annotations.xsd

<!--  New DWR capabilities-->
<dwra:url-mapping />
<dwra:annotation-config />

不是标准的，需要引入第三方包：DwrSpringAnnotations.jar,作为DWR.JAR的补充，可以使DWR引用spring-annntation方式实例化的bean，该jar在
http://www.nabble.com/attachment/15108217/0/annotations.war
下载

哦，DWR官方已经有Annotation了？那我的可以考虑不用了

1. 楼在吗,好像官方的XSD没有

   <dwra:url-mapping />  
   <dwra:annotation-config />

    这两个的支持了.怎么办?

貌似没怎么简化

还行吧，dwr跟spring是紧密结合了

<dwra:url-mapping />     
<dwra:annotation-config /> 

需要下载第三方的JAR，地址：
http://www.nabble.com/attachment/15108217/0/annotations.war