Behaviour of handleRequest() in MultiActionController

[va1224]

I extended a MultiActionController and added a bunch of methods that i mapped from my JSP page.

public ModelAndView addAccount(req,resp)
public ModelAndView updateAccount(req,resp)
public ModelAndView disableAccount(req,resp)

In my config file i had the following configuration settings
<bean id="paramResolver" class=".....ParameterMethodNameResolver">
<property name="methodParamNames">
<list>
<value>addAccount</value>
<value>updateAccount</value>
<value>disableAccount</value>
</list>
</property>
</bean>

I was expecting these methods to get called when i invoked each of the actions in my page however the only method that kept getting called was
handleRequest in my controller. When i removed this from the controller code i got a 404 error The requested resource () is not available message.

Can any one tell me why this happens and what more do i need to add to make this work?

Thanks in advance

[Marten Deinum]

[ code][/code ] tags please when posting code/configuration.

How are you accessing the links and what is happening really, do you get an exception somewhere?

[va1224]

I dont get any exceptions. I keep seeing "Inside handleRequestInternal" log message. None of my methods are getting called. Attaching my code:

<TABLE border=0 cellpadding=2 cellspacing=1 align="center">
		<TR>
			<TD align="center" noWrap>
				<input class=button type="submit" name="addAccount" value="Add New Account" onclick="dispatch('addAccount')"/>		
			</TD>
			<TD align="center" noWrap>
				<input class=button type="submit" name="updateAccount" value="Update Existing Account" onclick="dispatch('updateAccount')"/>		
			</TD>
			<TD align="center" noWrap>
				<input class=button type="submit" name="disableAccount" value="Disable Account" onclick="dispatch('disableAccount')"/>	
			</TD>
			<TD align="center" noWrap>
				<input class=button type="submit" name="clear" value="Clear">
			</TD>
			<TD align="center" noWrap>
				<input class=button type="submit" value="Exit">				
			</TD>
		</TR>
	</TABLE>

My Configuration File

<bean name="/actadmin.htm" class="eirapp.controller.AccountController">
		<property name="accountManager" ref="accountManager" />
		<property name="methodNameResolver">
			<ref bean="paramResolver" />
		</property>
	</bean>
	<bean id="paramResolver"
		class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver">
		<property name="methodParamNames">
		<list>
			<value>addAccount</value>
			<value>updateAccount</value>
			<value>disableAccount</value>
		</list>
		</property>
	</bean>

Controller Code

package eirapp.controller;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.multiaction.MultiActionController;

import eirapp.service.AccountManager;

public class AccountController extends MultiActionController {

	protected final Log logger = LogFactory.getLog(getClass());
	private AccountManager accountManager;

	public ModelAndView handleRequestInternal(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		logger.info("Inside handleRequestInternal");		
		String now = (new java.util.Date()).toString();
		Map<String, Object> myModel = new HashMap<String, Object>();
		myModel.put("now", now);
		myModel.put("accounts", this.accountManager.getAccounts());
		return new ModelAndView("actadmin", "model", myModel);
	}
	
	public ModelAndView addAccount(HttpServletRequest httpServletRequest,
			HttpServletResponse httpServletResponse) {
		logger
				.info("******Inside AccountController addAccount Method *******");
		return new ModelAndView("actadmin");
	}

	public ModelAndView updateAccount(HttpServletRequest httpServletRequest,
			HttpServletResponse httpServletResponse) {
		logger
				.info("******Inside AccountController updateAccount Method *******");
		return new ModelAndView("actadmin");
	}

	public ModelAndView disableAccount(HttpServletRequest httpServletRequest,
			HttpServletResponse httpServletResponse) {
		logger
				.info("******Inside AccountController disableAccount Method *******");
		return new ModelAndView("actadmin");
	}

	public void setAccountManager(AccountManager _accountManager) {
		this.accountManager = _accountManager;
	}

	public AccountManager getAccountManager() {
		return accountManager;
	}
}

[Marten Deinum]

You mustn't override the handleRequestInternal method, that will screw up the behavior of the MultiActionController.

[maverickthinker]

You are overriding the handleRequestInternal method so you should be calling the super class method so that resolved methods get invoked.

public ModelAndView handleRequestInternal(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		logger.info("Inside handleRequestInternal");
		ModelAndView modelAndView = super.handleRequestInternal(request, response);
		String now = (new java.util.Date()).toString();
		modelAndView.getModel().put("now", now);
		modelAndView.getModel().put("accounts", accountManager.getAccounts());
		return modelAndView;
	}

Hope this helps!

[va1224]

so as a best practice i should avoid this approach to override as far as possible. Can you tell me why this is so?

[va1224]

can you tell me how this will work

modelAndView.getModel()

because i keep a null pointer exception and i was wondering i am not setting the model any where to begin with and hence the get will result in a null. I am sorry ... just learning this thing and i may be missing something.

[maverickthinker]

According to the API that method never returns null (meaning you should get an empty map) & that is how the internal implementation seems to be. Are you getting a valid ModelAndView in the first place from the super call?

[va1224]

This is what i see in the log file:

INFO: Inside handleRequestInternal
Aug 20, 2008 10:40:04 AM org.springframework.web.servlet.mvc.multiaction.Mu ltiActionController handleNoSuchRequestHandlingMethod
WARNING: No matching handler method found for servlet request: path '/eirapp/actadmin.htm', method 'GET', parameters map[[empty]]

[va1224]

Ok...i see that in the documentation it says

Process the request and return a ModelAndView object which the DispatcherServlet will render. A null return value is not an error: It indicates that this object completed request processing itself, thus there is no ModelAndView to render.

And in my log i do see that the ModelAndView object = null. In such a case what do i do because if i execute a getModel on the ModelAndView object i am going to get a null pointer exception. Can you provide me a code snippet? That would help clear up my understanding.

My existing code looks like

public ModelAndView handleRequestInternal(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
logger.info("Inside handleRequestInternal");
ModelAndView modelAndView = super.handleRequestInternal(request,
				response);
logger.info("Inside handleRequestInternal "+modelAndView);
String now = (new java.util.Date()).toString();
modelAndView.getModel().put("now", now);
modelAndView.getModel().put("accounts", accountManager.getAccounts());
return modelAndView;

}

Thanks again.