Spring MVC - Multi Action Controller with Example

The MultiActionController in Spring MVC allows you to define multiple actions within a single controller. Instead of having a single handleRequest method (as in the older style of Spring controllers), the MultiActionController lets you have multiple methods where each method can handle a specific action.

Here's how to use MultiActionController:

1. Create the Controller:

This controller will extend MultiActionController and will have multiple methods to handle different actions.

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Controller
@RequestMapping("/multi")
public class MyMultiActionController extends MultiActionController {

    public ModelAndView add(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView("ResultPage");
        mav.addObject("message", "Add method called");
        return mav;
    }

    public ModelAndView delete(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView("ResultPage");
        mav.addObject("message", "Delete method called");
        return mav;
    }
}

2. Create the View (JSP):

Let's assume you have a JSP file named ResultPage.jsp under the /WEB-INF/views/ directory.

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>MultiAction Example</title>
</head>
<body>
    <h2>${message}</h2>
</body>
</html>

3. Spring Configuration:

Configure the MultiActionController in your Spring MVC configuration XML.

<!-- Enable Annotations -->
<context:annotation-config/>

<!-- Scan for annotated components -->
<context:component-scan base-package="com.example.demo.controller"/>

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

<!-- MultiAction Controller Configuration -->
<bean name="/multi.htm" class="com.example.demo.controller.MyMultiActionController">
    <property name="methodNameResolver">
        <bean class="org.springframework.web.servlet.mvc.multiaction.PropertiesMethodNameResolver">
            <property name="mappings">
                <props>
                    <prop key="/multi/add.htm">add</prop>
                    <prop key="/multi/delete.htm">delete</prop>
                </props>
            </property>
        </bean>
    </property>
</bean>

Here, the PropertiesMethodNameResolver is used to map URLs to method names.

4. Access the Actions:

Accessing the URL /multi/add.htm will call the add method.
Accessing the URL /multi/delete.htm will call the delete method.

While MultiActionController provided a unique way to structure controllers, it's worth noting that the more modern approach in Spring MVC is to use the @Controller annotation with specific @RequestMapping annotations for each action. This provides cleaner separation and more flexibility.

Spring MVC Multi Action Controller example:

The MultiActionController in Spring MVC allows you to define multiple methods to handle different actions in a single controller. Here's an example:

public class MyMultiActionController extends MultiActionController {

    public ModelAndView action1(HttpServletRequest request, HttpServletResponse response) {
        // Handle action1
        return new ModelAndView("action1View");
    }

    public ModelAndView action2(HttpServletRequest request, HttpServletResponse response) {
        // Handle action2
        return new ModelAndView("action2View");
    }
}

Spring MVC Multi Action Controller configuration:
In older versions of Spring, configuring a MultiActionController involves defining it in the Spring configuration XML file.
```
<bean name="/myController.htm" class="com.example.MyMultiActionController" />
```

Spring 3 MultiActionController example:

In Spring 3, you can use MultiActionController as follows:

public class MyMultiActionController extends MultiActionController {

    public ModelAndView action1(HttpServletRequest request, HttpServletResponse response) {
        // Handle action1
        return new ModelAndView("action1View");
    }

    public ModelAndView action2(HttpServletRequest request, HttpServletResponse response) {
        // Handle action2
        return new ModelAndView("action2View");
    }
}

And in the XML configuration:

<bean name="/myController.htm" class="com.example.MyMultiActionController" />

Migrating from MultiActionController to annotated controllers in Spring MVC:

To migrate from MultiActionController to annotated controllers, create a new class annotated with @Controller and define methods using @RequestMapping for each action. Update the Spring configuration to scan the new controllers.

@Controller
public class MyController {

    @RequestMapping("/action1")
    public ModelAndView action1(HttpServletRequest request, HttpServletResponse response) {
        // Handle action1
        return new ModelAndView("action1View");
    }

    @RequestMapping("/action2")
    public ModelAndView action2(HttpServletRequest request, HttpServletResponse response) {
        // Handle action2
        return new ModelAndView("action2View");
    }
}

And in the XML configuration:

<context:component-scan base-package="com.example" />