struts2入门

好久没有动博客了。今天看了一下慕课网的视频，简单了解一下struts2。

首先是在项目中引入struts2的文件，有一个比较简单的方法就是可以直接右键项目MyEclipse->Project facets->install struts2

然后是在web.xml中进行相应的配置(filter过滤器)，这里和不使用框架基本类似，代码如下，系统好像会自动生成默认的过滤，如下

 <?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>TryStruts2</display-name>
   <filter>
     <filter-name>struts2</filter-name>
     <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
       <init-param>
           <param-name>struts.action.extension</param-name>
           <param-value>do</param-value>
       </init-param>
   </filter>
   <filter-mapping>
     <filter-name>struts2</filter-name>
     <url-pattern>/*</url-pattern>
   </filter-mapping>
   <welcome-file-list>
     <welcome-file>index.html</welcome-file>
     <welcome-file>index.htm</welcome-file>
     <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
   <!--
   <filter>
     <filter-name>struts2_1</filter-name>
     <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
   </filter>
   <filter-mapping>
     <filter-name>struts2_1</filter-name>
     <url-pattern>*.action</url-pattern>
   </filter-mapping>
    -->
 </web-app>

web.xml

然后写一个action文件，如下

 package com.imooc.action;

 import javax.servlet.http.HttpServletRequest;
 import com.opensymphony.xwork2.ActionSupport;

 public class HelloWorldAction extends ActionSupport {

     private HttpServletRequest request;

     //helloworld.action

     public String add(){
 //        return SUCCESS;
         return "add";
     }

     public String update(){
 //        return SUCCESS;
         return "update";
     }
     @Override
     public String execute() throws Exception {
         System.out.println("执行Action");
         return SUCCESS;
     }

 }

HelloWorldAction

然后是struts.xml文件，里面通过include引入了另外一个配置文件helloworld.xml

 <?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>
     <include file="helloworld.xml"></include>

     <constant name="struts.action.extension" value="do"></constant>

     <!-- 感叹号方式 -->
     <!-- http://localhost:8080/TryStruts2/helloworld!add.action -->
     <constant name="struts.enable.DynamicMethodInvocation" value="false"></constant>
 </struts>

struts.xml

<constant name="struts.action.extension" value="do"></constant>这行代码是进行访问后缀的设置，也可以在web.xml中设置,value用逗号分隔

有三种动态的方法调用action ，一种是指定method属性，一种是用感叹号方式，但是最推荐的是用通配符的方式，所以前两种方式在代码中注释了

<constant name="struts.enable.DynamicMethodInvocation" value="false"></constant>   value设置为true就能开启感叹号访问方式

下面是helloworld.xml的代码，里面有注释就不进行详细分析了

 <?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>
     <!-- 映射 -->
     <!-- Action搜索顺序 1.判断当前包是否存在(存在2.1 不存在2.2) 2.1判断action是否存在，不存在则去默认namespase的package里面寻找action
         2.2检查上一级路径的package是否存在，直到默认namespace -->

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

         <!-- 默认action -->
         <default-action-ref name="index"></default-action-ref>
             <action name="index">
                 <result>/error.jsp</result>
             </action>

         <action name="*_*_*" method="{2}" class="com.imooc.{3}.{1}Action">
             <result>/result.jsp</result>
             <result name="add">/{2}.jsp</result>
             <result name="update">/{2}.jsp</result>
         </action>

         <!-- 指定method属性 <action name="addAction" method="add" class="com.imooc.action.HelloWorldAction">
             <result>/add.jsp</result> </action> <action name="updateAction" method="update"
             class="com.imooc.action.HelloWorldAction"> <result>/update.jsp</result> </action> -->
     </package>

 </struts>

helloworld

比如上面的配置访问路径就为http://localhost:8080/TryStruts2/HelloWorld_add_action.do或者action或者html

下面介绍一下action接收参数的3个方式 ，这里推荐一篇博客，写的很详细规范。但是我还是自己写一遍毕竟强迫症。

http://www.cnblogs.com/bukudekong/archive/2012/03/29/2423064.html

表示感觉炒鸡神奇，再次暴露看的书少- -之前都是用的request

1.使用Action的属性接收参数

首先是login.jsp，主要是一个表单，注意input的name属性

<form action="LoginAction.action" method="post">
用户名：<input type="text" name="username" />
密码:<input type="password" name="password" />
<input type="submit" value="提交" />
</form>

然后是LoginAction

 package com.imooc.action;

 import com.opensymphony.xwork2.ActionSupport;

 public class LoginAction extends ActionSupport {

     //action 属性取值
     private String username;
     private String password;

     public String login(){
         System.out.println(username);

         return SUCCESS;
     }

     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;
     }
 }

LoginAction

最后在helloworld.xml进行action配置

<action name="LoginAction" method="login" class="com.imooc.action.LoginAction">
<result>/success.jsp</result>
</action>

2.使用DomainModel接收参数

首先是login.jsp  input的name相应的更改了

<form action="LoginAction.action" method="post">
用户名：<input type="text" name="user.username" />
密码:<input type="password" name="user.password" />
<input type="submit" value="提交" />
</form>

然后是一个po实体类

 package com.imooc.po;

 public class User {

     private String username;
     private String password;
     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;
     }
 }

User

然后是LoginAction

 package com.imooc.action;

 import com.imooc.po.User;
 import com.opensymphony.xwork2.ActionSupport;

 public class LoginAction extends ActionSupport {

     private User user;

     public String login(){
         System.out.println(user.getUsername());

         return SUCCESS;
     }

     public User getUser() {
         return user;
     }

     public void setUser(User user) {
         this.user = user;
     }
 }

LoginAction

3.使用ModelDriven接收参数，感觉这个好叼

首先是表单 input的name改了，使用前要加这个，类似jstl标签<%@ taglib prefix="s" uri="/struts-tags" %>

<form action="LoginAction.action" method="post">
用户名：<input type="text" name="username" /><s:fielderror name="username"></s:fielderror>
密码:<input type="password" name="password" />
书籍1:<input type="text" name="bookList[0].username" />
书籍2:<input type="text" name="bookList[1].username" />
年龄：<input type="text" name="age" />
<input type="submit" value="提交" />
</form>

然后是实体类

 package com.imooc.po;

 import java.util.List;

 public class User {

     private String username;
     private String password;
     private int age;
     private List<User> bookList;
     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;
     }
     public List<User> getBookList() {
         return bookList;
     }
     public void setBookList(List<User> bookList) {
         this.bookList = bookList;
     }
     public int getAge() {
         return age;
     }
     public void setAge(int age) {
         this.age = age;
     }

 }

User

然后是LoginAction

 package com.imooc.action;

 import com.imooc.po.User;
 import com.opensymphony.xwork2.ActionSupport;
 import com.opensymphony.xwork2.ModelDriven;

 public class LoginAction extends ActionSupport implements ModelDriven<User>{

     private User user=new User();

     public String login(){

         System.out.println(user.getUsername());
         System.out.println(user.getBookList().get(0).getUsername());
         System.out.println(user.getBookList().get(1).getUsername());

         return SUCCESS;
     }

     @Override
     public User getModel() {
         return user;
     }

     @Override
     public void validate(){
         if(user.getUsername()==null||"".equals(user.getUsername())){
             this.addFieldError("username", "用户名不能为空");
         }
     }
 }

LoginAction

validate()方法用于验证用户名是否为空

在helloworld.xml中添加 用户处理表单验证不正确时返回登陆页

<action name="LoginAction" method="login" class="com.imooc.action.LoginAction">
<result>/success.jsp</result>
<!-- 表单验证不正确 -->
<result name="input">/login.jsp</result>
</action>

下面是5中处理结果类型

写的有点乱，简单记录一下