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。
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。
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";
}
}
}
<?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>
<%@ 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>
<%@ 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>
<%@ 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>
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。
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;
}
}
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";
}
}
}
<?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>
<%@ 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>
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。