Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

Migrate from Struts to Spring MVC in 6 Steps

DZone's Guide to

Migrate from Struts to Spring MVC in 6 Steps

· Java Zone
Free Resource

Learn how to troubleshoot and diagnose some of the most common performance issues in Java today. Brought to you in partnership with AppDynamics.

In this tutorial we will see the migration of a web application made in struts to spring mvc. Struts to Spring migration we will do step by step. Here I will share you step by step approach to migrate application from Struts to Spring using annotations.

Step 1: Replace struts libraries with spring libraries.

Firstly while migrating from struts to spring we have to replace our struts related libraries with spring libraries in lib folder.

migrate from struts2 to spring3


I have mentioned basic libraries of both struts and spring for your clarification.

Struts basic libraries :

  1. struts.jar

  2. struts-legacy.jar

  3. etc..

Have you ever use : Javadoc comment in Java

Spring basic libraries :

  1. standard.jar

  2. org.springframework.asm-4.0.1.RELEASE-A.jar

  3. org.springframework.beans-4.0.1.RELEASE-A.jar

  4. org.springframework.context-4.0.1.RELEASE-A.jar

  5. org.springframework.core-4.0.1.RELEASE-A.jar

  6. org.springframework.expression-4.0.1.RELEASE-A.jar

  7. org.springframework.web.servlet-4.0.1.RELEASE-A.jar

  8. org.springframework.web-4.0.1.RELEASE-A.jar

  9. etc..

Step 2: Change made to web.xml file for struts to spring migration

In this step we have to remove Action filter dispatcher for the web.xml and add Spring dipatcher servlet as Front controller

Work on new technology : Create and manage cloud applications using Java

In Strut application web.xml look like as follows

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">

<display-name>Struts2MyFirstApp</display-name>

<filter>

<filter-name>struts2</filter-name>

<filter-class>

org.apache.struts2.dispatcher.FilterDispatcher

</filter-class>

</filter>



<filter-mapping>

<filter-name>struts2</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<welcome-file-list>

<welcome-file>Login.jsp</welcome-file>

</welcome-file-list>

</web-app>


In Spring application web.xml look like as follows

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">

<display-name>springApp</display-name>

<servlet>

<servlet-name>springApp</servlet-name>

<servlet-class>

org.springframework.web.servlet.DispatcherServlet

</servlet-class>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>springApp</servlet-name>

<url-pattern>/</url-pattern>

</servlet-mapping>

</web-app>


Step 3: Replace config files for struts to spring migration

Now replace all struts configuration files to spring configuration file as follows

In Struts application struts configuration file-

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"

"http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

<constant name="struts.enable.DynamicMethodInvocation" value="false" />

<constant name="struts.devMode" value="false" />

<constant name="struts.custom.i18n.resources" value="myapp" />

<package name="default" extends="struts-default" namespace="/">

<action name="login" class="com.geekonjavaonjava.struts2.login.LoginAction">

<result name="success">Welcome.jsp</result>

<result name="error">Login.jsp</result>

</action>

</package>

</struts>


In Spring application spring configuration file as follows

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:context="http://www.springframework.org/schema/context"

xmlns:p="http://www.springframework.org/schema/p"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-4.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-4.0.xsd">

<context:component-scan base-package="com.geekonjavaonjava.spring.login.controller" />

<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>

</beans> <span style="font-family: Times New Roman;"><span style="white-space: normal;">

</span></span>


Here, <context:component-scan> tag is used, so that spring will load all the components from given package i.e. "com.geekonjavaonjava.spring.login.controller".

We can use different view resolver, here I have used InternalResourceViewResolver. In which prefix and suffix are used to resolve the view by prefixing and suffixing values to the object returned by ModelAndView in action class.

For other three Steps see the reference

Understand the needs and benefits around implementing the right monitoring solution for a growing containerized market. Brought to you in partnership with AppDynamics.

Topics:
spring framework ,spring mvc ,java ,spring ,struts2 ,web dev ,html5

Published at DZone with permission of Das Nic. See the original article here.

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}