Mapping a single controller to several beans in spring

Question

I need to create several beans for my static pages with different IDs using a single controller class which has an attribute to define a jsp name to be displayed.

I used to do this with an older version using FormControllers but I cannot in version 3.2.4 I checked several topics and understand that spring beans are singletons but I want to know if this is possible or if there is a work-around without creating empty controller classes for each page.

Here is the BaseController class:

    public class BaseController extends AbstractController {

    public String contentPage;

    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mv = new ModelAndView("common/mainlayout");

        if(contentPage != null && !contentPage.equals("")){
            mv.addObject("mainContent", "maincontent/" + contentPage);
            mv.addObject("mainMenuSelect", contentPage);
        }

        return mv;
    }

    public String getContentPage() {
        return contentPage;
    }
    public void setContentPage(String contentPage) {
        this.contentPage = contentPage;
    }
}

Here is my mapping in spring-servlet.xml Note that I also tried defining class of each bean using my BaseController

<bean id="urlMapping"
    class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="mappings">
        <props>

            <!-- STATIC PAGES -->
            <prop key="/index.dlg">indexPageController</prop>
            <prop key="/faq.dlg">faqController</prop>
            <prop key="/howto.dlg">howtoController</prop>
            <prop key="/contactUs.dlg">contactUsController</prop>
            <prop key="/aboutUs.dlg">aboutUsController</prop>

            <!-- DYNAMIC PAGES -->
            <prop key="/postBox.dlg">postBoxController</prop>
            <prop key="/invoiceBox.dlg">invoiceController</prop>
        </props>
    </property>

    <property name="interceptors">
        <list>
            <ref bean="siteInterceptor" />
        </list>
    </property>

</bean>

<bean id="siteInterceptor" class="com.entegrator.spring.interceptor.SiteInterceptor"></bean>

<!-- STATIC PAGE CONTROLLERS -->
<bean id="baseController" abstract="true" class="com.entegrator.spring.controller.BaseController" />

<bean id="indexPageController" parent="baseController" >
    <property name="contentPage" value="index" />
</bean>

<bean id="faqController" parent="baseController" >
    <property name="contentPage" value="faq" />
</bean>

<bean id="howtoController" parent="baseController" >
    <property name="contentPage" value="howto" />
</bean>

<bean id="contactUsController" parent="baseController" >
    <property name="contentPage" value="contactUs" />
</bean>

<bean id="aboutUsController" parent="baseController" >
    <property name="contentPage" value="aboutUs" />
</bean>
<!-- STATIC PAGE CONTROLLERS END -->


<!-- DYNAMIC PAGE CONTROLLERS -->
<bean id="postBoxController" class="com.entegrator.spring.controller.PostBoxController">
    <property name="postBoxManager" ref="postBoxManager" />
</bean>
<bean id="invoiceController" class="com.entegrator.spring.controller.InvoiceController">
    <property name="postBoxManager" ref="postBoxManager" />
</bean>
<!-- DYNAMIC PAGE CONTROLLERS END -->

my web.xml is:

<display-name>EntegratorPortal</display-name>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>


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

    <servlet>
        <servlet-name>spring</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>spring</servlet-name>
        <url-pattern>*.dlg</url-pattern>
    </servlet-mapping>

Here is my error log:

 SEVERE: StandardWrapper.Throwable
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping#0' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]: Initialization of bean failed; nested exception is java.lang.IllegalStateException: Cannot map handler 'faqController' to URL path [/base*]: There is already handler 'indexPageController' mapped.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:529)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:651)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:599)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:665)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:518)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:459)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    at javax.servlet.GenericServlet.init(GenericServlet.java:160)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:865)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:136)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.IllegalStateException: Cannot map handler 'faqController' to URL path [/base*]: There is already handler 'indexPageController' mapped.
    at org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.registerHandler(AbstractUrlHandlerMapping.java:294)
    at org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.registerHandler(AbstractUrlHandlerMapping.java:266)
    at org.springframework.web.servlet.handler.AbstractDetectingUrlHandlerMapping.detectHandlers(AbstractDetectingUrlHandlerMapping.java:82)
    at org.springframework.web.servlet.handler.AbstractDetectingUrlHandlerMapping.initApplicationContext(AbstractDetectingUrlHandlerMapping.java:58)
    at org.springframework.context.support.ApplicationObjectSupport.initApplicationContext(ApplicationObjectSupport.java:119)
    at org.springframework.web.context.support.WebApplicationObjectSupport.initApplicationContext(WebApplicationObjectSupport.java:72)
    at org.springframework.context.support.ApplicationObjectSupport.setApplicationContext(ApplicationObjectSupport.java:73)
    at org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces(ApplicationContextAwareProcessor.java:117)
    at org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization(ApplicationContextAwareProcessor.java:92)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:396)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1475)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
    ... 32 more

Thanks for your help

Answer 1

Could you not simply have methods annotated with @RequestMapping(value="/foo" method="RequestMethod.GET") within your one controller for each of your pages?

That seems to be the simplest solution.

Your controller would look something like this:

@Controller
public class BaseController
{

    @RequestMapping(value="/index", method="RequestMethod.GET")
    public String returnIndexPage()
    {
        return "Your Index JSP Page Location Here";
    }

    @RequestMapping(value="/faq", method="RequestMethod.GET")
    public String returnFAQPage()
    {
         return("Your FAQ JSP Page Location Here";
    }

etc...

You could modify it to only return your content page variable if you like.

That would certainly work too.

Let me know how you get on.

Answer 2

Why not leverage the new spring @Controller and @RequestMapping annotations? That way you only need a single controller.

@Controller
public class StaticController {


    @RequestMapping({"/index.dlg", "/howto", // The rest of your mappings}
    public String handleStatic(HttpServletRequest request, Model model) {
        String contentPage = //Extract page-name from request 
        model.addObject("mainContent", "maincontent/" + contentPage);
        model.addObject("mainMenuSelect", contentPage);  
        return "common/mainlayout";      
    }
}

This controller can then be detected and setup by using the RequestMappingHandlermapping and executed by the RequestMappingHandlerAdapter (those are registered by using <mvc:annotation-driven /> in your xml configuration).

Or utilize springs view-controller ( <mvc:view-controller .. /> ) and add an interceptor to add the needed attributes to the model

<mvc:view-controller path="/index.dlg" view-name="common/mainlayout" />
<mvc:view-controller path="/faq.dlg" view-name="common/mainlayout" />

<mvc:interceptors>
    <mvc:interceptor>
        <mapping path="/index.dlg" />
        <mapping path="/faq/dlg" />
        <bean class="YourInterceptor" />
    </mvc:interceptor>
</mvc:interceptors>

Drawback of this approach is that you are basically duplicating your mappings (once for the controller and once for the interceptor).

Links

1. Implementing Controllers reference guide
2. View Controllers reference guide
3. Configuring Interceptors reference guide