How do I map DWR 3 properly using Spring MVC?

Question

I'm trying to integrate Spring 3.1.1.RELEASE with DWR 3 (v 3.0.0-rc2). I'm using Spring MVC but am not able to get the setup to work properly. Spring isn't able to map /dwr/engine.js (or anything else with /dwr properly. I get this error in my app log files …

11:43:31,237 WARN  [org.springframework.web.servlet.PageNotFound] (http--127.0.0.1-8080-4) No mapping found for HTTP request with URI [/myapp-1.0-SNAPSHOT/dwr/engine.js] in DispatcherServlet with name 'dispatcher'

Here is my web.xml …

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
                            http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <display-name>SB Admin</display-name>

    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/jboss-as-spring-mvc-context.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:/META-INF/spring/applicationContext-myapp.xml</param-value>
    </context-param>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

And here is my spring application context file (the DWR configuration is at the end):

<?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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:dwr="http://www.directwebremoting.org/schema/spring-dwr"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.directwebremoting.org/schema/spring-dwr
http://www.directwebremoting.org/schema/spring-dwr-3.0.xsd">

    <context:component-scan base-package="org.myco.subco" />

    <!-- Enable annotation driven controllers, validation etc... -->
    <mvc:annotation-driven />

    <!-- the mvc resources tag does the magic -->
    <mvc:resources mapping="/resources/**" location="/resources/" />

    <util:properties id="applicationProperties" location="classpath:application.properties" />

    <bean id="messageSource"
        class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basename" value="classpath:messages" />
    </bean>

    <bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
        <property name="jndiName" value="java:jboss/datasources/MySqlDS" />
    </bean>

    <bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceXmlLocation" value="classpath:META-INF/persistence.xml" />
        <property name="persistenceUnitName" value="myappunit" />
        <property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="sharedEntityManager"
        class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <tx:annotation-driven />

    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/WEB-INF/views/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

    <dwr:annotation-scan base-package="org.myco.subco" scanDataTransferObject="true" scanRemoteProxy="true" />
    <dwr:url-mapping /> 
    <dwr:controller id="dwrController" debug="true" />
    <dwr:configuration />

</beans>

Any ideas what I'm missing?

Answer 1

I was able to solve my problem using this web.xml configuration ...

<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/jboss-as-spring-mvc-context.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/dwr/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

and this Spring MVC config ...

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

<!-- DWR will scan all Spring managed beans containing @RemoteProxy or @RemoteMethod 
    annotations and register Creator proxies for them. This will NOT scan any 
    classes not managed by Spring. -->
<dwr:annotation-config id="springdwr" />

<!-- DWR will scan the classpath and search classes containing @RemoteProxy 
    or @RemoteMethod annotations. This will register the beans and Creator proxies 
    for these classes. -->
<dwr:annotation-scan base-package="org.collegeboard.springboard"
    scanDataTransferObject="true" scanRemoteProxy="true" />

<!-- DWR will map util.js and engine.js files to the dwrController. You 
    can then include this files as external Javascript references from your JSP -->
<dwr:url-mapping />

<!-- Defines the dwrController. During production, set the debug property 
    to false -->
<dwr:controller id="dwrController" debug="true" />

<!-- This is required if you want to configure any beans not managed by 
    Spring. Leaving it enabled doesn't do any negative effects. Here's a sample 
    config: -->
<dwr:configuration />

Answer 2

It looks like you have all the parts you need, but you need to join them up. I can't see any mapping from Spring MVC through to the DWR controller, which would be why Spring MVC doesn't recognise those URLs.

Adding the following to your Spring application context configuration file should do it:

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

<bean id="viewMappings" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="alwaysUseFullPath" value="true" />
    <property name="urlMap">
         <map>
              <entry key="/dwr/**/*" value-ref="dwrController" />
         </map>
    </property>
</bean>

In your case I think that's all you need.

However I've had problems with some Java application servers when they automatically handle *.js URLs with their internal static file handler instead of going to Java code. If you have that problem, change your servlet-mapping in your web.xml to ensure that Spring handles those URLs instead of the inbuilt file hander. For example:

<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>