基于struts的系统迁移到SpringMVC架构上来，共分六部曲，让系统一部一部迁移过来，本文讲的知识点以Struts2 to Spring4，但是针对其他应用场景也是可以参考的。
Step 1: 替换基本的框架库。
Firstly while migrating from struts to spring we have to replace our struts related libraries with spring libraries in lib folder.
I have mentioned basic libraries of both struts and spring for your clarification.
Struts basic libraries :
- struts.jar
- struts-legacy.jar
- etc..
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Spring basic libraries :
- standard.jar
- org.springframework.asm-4.0.1.RELEASE-A.jar
- org.springframework.beans-4.0.1.RELEASE-A.jar
- org.springframework.context-4.0.1.RELEASE-A.jar
- org.springframework.core-4.0.1.RELEASE-A.jar
- org.springframework.expression-4.0.1.RELEASE-A.jar
- org.springframework.web.servlet-4.0.1.RELEASE-A.jar
- org.springframework.web-4.0.1.RELEASE-A.jar
- etc..
Step 2: 修改web.xml配置文件
In this step we have to remove Action filter dispatcher for the web.xml and add Spring dipatcher servlet as Front controller
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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>dispatcher</display-name>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
Step 3: 替换Struts本身的配置文件
Now replace all struts configuration files to spring configuration file as follows
In Struts applivation 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>
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".
Use this in Struts2 : Get value of struts property tag into jsp variable
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.
Step 4: 修改JSP文件
While migration an application from struts to spring we need to change in jsp file as following
Firstly replace all tlds-
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %> <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %> <%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %> <%@ taglib uri="http://struts.apache.org/tags-tiles" prefix="tiles" %>
Replace these with following spring taglib's :
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%> <%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
In Struts :
<html:form action="/addLogin" method="post">
In Spring :
<form:form method="POST" commandName="loginForm" name="loginForm" action="login.do">
Here commandName is going to map with corresponding formbean for that jsp. Next we will see, how action is getting called with spring 4 annotations.
Step 5: 修改Action 类文件
Now following changes need to be done in action classes for struts to spring migration using annotations-
Struts Action:
package com.geekonjavaonjava.struts2.login;
import com.opensymphony.xwork2.ActionSupport;
/**
* @author geekonjava
*
*/
@SuppressWarnings("serial")
public class LoginAction extends ActionSupport{
private String username;
private String password;
public String execute() {
if (this.username.equals("geekonjava")
&& this.password.equals("sweety")) {
return "success";
} else {
addActionError(getText("error.login"));
return "error";
}
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
Spring action
package com.geekonjavaonjava.spring.login.controller;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
/**
* @author GeekOnJava
*
*/
@Controller
public class LoginController {
@RequestMapping(value="/login.do", method = RequestMethod.GET)
public String doLogin(ModelMap model, LoginForm loginForn) {
if (this.username.equals("geekonjava")
&& this.password.equals("sweety")) {
model.addAttribute("message", "Login Success");
} else {
model.addAttribute("message", "Login Failure");
}
return "home";
}
}
Step 6: 修改前端验证机制
In struts JSP file validation changes as follows
<% ActionErrors actionErrors = (ActionErrors)request.getAttribute("org.apache.struts.action.ERROR"); %>
In Spring JSP file as follows-
<form:errors path="*" cssClass="error" />
参考链接
- 把系统从Struts2 迁移到 Spring MVC六大步总结
- SpringBoot系列——i18n国际化
- SpringMVC：Struts2区别、搭建应用、流程处理、核心控制器
- Spring MVC国际化（i18n）和本地化（L10n）示例
- Spring 国际化遇到的坑 No message found under code ‘xxx.xxxx‘ for locale ‘zh_CN‘
- 项目整理：springmvc国际化配置messageSource（以中英文为例）
- Spring核心——MessageSource实现国际化
- springMVC访问静态资源——js、css、img等资源访问不到
- springmvc将后台的数据展示到jsp页面
- Model、ModelMap和ModelAndView的使用详解
- SpringMVC原理分析 | 数据处理：ModelAndView
