struts2工作流程

从struts2Demo1中看struts2的工作流程

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <%@ taglib prefix="s" uri="/struts-tags"%> 
 5 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 6 <html xmlns="http://www.w3.org/1999/xhtml">
 7 <head>
 8 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 9 <title>Login</title>
10 </head>
11 <body>
12 
13     <s:form action="Login">
14         <s:label>登录系统</s:label>
15         <s:textfield name="userName" label="用户名："></s:textfield>
16         <s:password name="password" label="密码："></s:password>
17         <s:submit value="登录"></s:submit>
18     </s:form>
19 
20 </body>
21 </html>

web.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <web-app version="3.0" 
 3     xmlns="http://java.sun.com/xml/ns/javaee" 
 4     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 5     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 6     http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
 7     
 8     <display-name>struts2Demo1</display-name>
 9 
10     <filter>
11         <filter-name>struts2</filter-name>
12         <!-- StrutsPrepareAndExecuteFilter用来初始化struts2，并处理所有的Web请求 -->
13         <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
14     </filter>
15 
16     <filter-mapping>
17         <filter-name>struts2</filter-name>
18         <url-pattern>/*</url-pattern>
19     </filter-mapping>
20 
21     <welcome-file-list>
22         <welcome-file>index.html</welcome-file>
23         <welcome-file>index.jsp</welcome-file>
24     </welcome-file-list>
25 
26 </web-app>

LoginAction.java

 1 package edu.dzu.action;
 2 
 3 import com.opensymphony.xwork2.ActionSupport;
 4 
 5 public class LoginAction extends ActionSupport {
 6 
 7     /**
 8      * 
 9      */
10     private static final long serialVersionUID = 1L;
11 
12     private String userName;
13     private String password;
14     
15     @Override
16     public String execute(){
17         if( userName.equals("admin") && password.equals("1234") ){
18             return SUCCESS;
19         }else{
20             return LOGIN;
21         }
22     }
23     
24     public String getUserName() {
25         return userName;
26     }
27     public void setUserName(String userName) {
28         this.userName = userName;
29     }
30     public String getPassword() {
31         return password;
32     }
33     public void setPassword(String password) {
34         this.password = password;
35     }
36 
37 }

struts.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE struts PUBLIC
 3     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
 4     "http://struts.apache.org/dtds/struts-2.3.dtd">
 5 
 6 <struts>
 7 
 8     <package name="package" extends="struts-default">
 9         <global-results>
10             <result name="login">/login/login.jsp</result>
11         </global-results>
12         <action name="Login" class="edu.dzu.action.LoginAction">
13             <result name="success">/login/loginSuccess.jsp</result>
14         </action>
15     </package>
16     <!-- Add packages here -->
17 
18 </struts>

loginSuccess.jsp

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <%@ taglib prefix="s" uri="/struts-tags" %>
 5 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 6 <html xmlns="http://www.w3.org/1999/xhtml">
 7 <head>
 8 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 9 <title>Login Success</title>
10 </head>
11 <body>
12     <h1> 用户&nbsp;<s:property value="userName" />&nbsp;登录成功</h1>
13     <hr/>
14 </body>
15 </html>

Struts2工作流程：

1、访问JSP页面http:localhost:8080/strutsDemo1/login/login.jsp

2、提交表单后数据提交给/struts2Demo/Login.action

3、struts2截获所有请求

4、查找struts.xml文件，找到Login.action的映射类LoginAction

5、生成一个LoginAction实例，将提交的数据set到action实例中

6、调用action实例的execute()方法处理业务逻辑

7、forward到JSP页面显示结果，并销毁该action实例

struts2官方文档中的struts2架构图

注意：
org.apache.struts2.dispatcher.FilterDispatcher 
   Since Struts 2.1.3, use StrutsPrepareAndExecuteFilter instead or StrutsPrepareFilter and StrutsExecuteFilter if needing using 
the ActionContextCleanUp filter in addition to this one