在struts2中action的分类有:继承 ActionSupport 实现 Action,模型驱动(ModelDriven)的 Action,多方法的 Action三种方式。
1、继承 ActionSupport 实现 Action
通过继承 ActionSupport 来实现 Action 是我们的推荐做法,因为 ActionSupport 中提供了输入验证、国际化、execute 等常用方法,使得编写 Action 时代码很简单。
1.1 UserAction.java
package com.lzugis.action; import com.opensymphony.xwork2.ActionSupport; public class UserAction extends ActionSupport { /** * */ private static final long serialVersionUID = 1L; private String username; private String userpass; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getUserpass() { return userpass; } public void setUserpass(String userpass) { this.userpass = userpass; } @Override public String execute() throws Exception { if (username.equals("admin") && userpass.equals("admin")) { return "success"; } else { return "error"; } } }
1.2 struts.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> <!-- 定义包管理配置的action 继承struts-default.xml中的配置 --> <package name="action" extends="struts-default"> <!-- 定义Action(login.action) --> <action name="login" class="com.lzugis.action.UserAction"> <!-- 定义转发路径对应的字符串名 --> <result name="success">/Success.jsp</result> <result name="error">/Error.jsp</result> </action> </package> </struts>
1.3 userlogin.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>用户登录</title> </head> <body style="font-family:Times New Roman"> <form action="login.action" method="post"> 用户名: <!-- 参数名和action中的属性名一样 --> <input type="text" name="username"><br> 密 码: <input type="password" name="userpass"> <br> <input type="submit" name="subm" value="提交"> <input type="reset" name="reset" value="取消"> </form> </body> </html>
1.4 action响应结果
1.4.1 Success.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@ taglib uri="/struts-tags" prefix="s"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>登录成功</title> </head> <body> <h1>欢迎<s:property value="username" />,登录</h1> </body> </html>
1.4.2 Error.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>登陆错误</title> </head> <body> <h1>用户名或者密码错误</h1> </body> </html>
2、模型驱动(ModelDriven)的 Action
Struts2 的 Action 属于 MVC 模型层, Action 中的方法代表业务逻辑, Action 中的属性代表请求中的参数,当页面请求参数较多的时候,把过多的参数对象的属性定义在 Action 中不太符合 Struts 所倡导的松耦合原则,所以我们推荐单独用 JavaBean 来封装参数,在 Action中为 JavaBean 赋值,这就是 ModelDriven 的 Action。模型驱动的 Action 要求 Action
实现ModelDriven 接口,假如登录页面需要传输参数 username 和 userpass,我们把这 2 个参数封装在一个数据的 JavaBean 中,然后在 Action 中定义该 JavaBean 为 Model 即可。
2.1 UserInfo.java
package com.lzugis.javabean; public class UserInfo { private String username,userpass; public String getUsername() { return username; } public void setUsername(String username) { this.username=username; } public String getUserpass() { return userpass; } public void setUserpass(String userpass) { this.userpass=userpass; } }
2.2 UserinfoAction.java
package com.lzugis.action; import com.lzugis.javabean.UserInfo; import com.opensymphony.xwork2.ActionSupport; import com.opensymphony.xwork2.ModelDriven; public class UserinfoAction extends ActionSupport implements ModelDriven<UserInfo> { /** * */ private static final long serialVersionUID = 1L; private UserInfo model; @Override public UserInfo getModel() { if(model == null) { model = new UserInfo(); } return model; } @Override public String execute() throws Exception { if (model.getUsername().equals("admin") && model.getUserpass().equals("admin")) { return "success"; } else { return "error"; } } }
2.3 struts.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> <!-- 定义包管理配置的action 继承struts-default.xml中的配置 --> <package name="action" extends="struts-default"> <!-- 定义Action(user.action) --> <action name="user" class="com.lzugis.action.UserinfoAction"> <!-- 定义转发路径对应的字符串名 --> <result name="success">/Success.jsp</result> <result name="error">/Error.jsp</result> </action> </package> </struts>
2.4 user.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>用户登录</title> </head> <body style="font-family:Times New Roman"> <form action="user.action" method="post"> 用户名: <!-- 参数名和action中的属性名一样 --> <input type="text" name="model.username"><br> 密 码: <input type="password" name="model.userpass"> <br> <input type="submit" name="subm" value="提交"> <input type="reset" name="reset" value="取消"> </form> </body> </html>
2.5 action结果
与1相同,在此不在赘述。
本实例通过struts中action的两种不同方式,实现了用户登陆的验证。相比较继承ActionSupport实现action,模型驱动的action比较方便。继承ActionSupport实现action,如果实体类的属性非常多,那么Action中也要定义相同的属性,这样显得比较繁琐。