Strust2之拦截器入门实例

||实现一个拦截器||

        功能：

                判断用户请求的的action类是否为LoginAction,是则继续操作，否则检查用户是否已经登录;

                如果已登录则继续操作，否则跳转到登录页面。

        1、项目结构

2、项目代码：

<?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_2_5.xsd" id="WebApp_ID" version="2.5">
	<display-name>Interceptor_01</display-name>

	<filter>
		<filter-name>struts2</filter-name>
		<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
	</filter>

	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

<?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>
	<package name="struts2" extends="struts-default">

		<interceptors>
			<interceptor name="myInterceptor" class="cn.interceptor.MyInterceptor"></interceptor>
			<interceptor-stack name="interceptortack">
				<interceptor-ref name="myInterceptor" />
				<interceptor-ref name="defaultStack" />
			</interceptor-stack>
		</interceptors>
		<default-interceptor-ref name="interceptortack" />

		<global-results>
			<result name="unLogin">/login.jsp</result>
			<result name="error">/login.jsp</result>
		</global-results>

		<action name="login" class="cn.action.LoginAction" method="Login">
			<result name="success">/index.jsp</result>
		</action>
		
		<action name="addUser" class="cn.action.UserAction" method="addUser">
			<result name="success">/index.jsp</result>
		</action>
	</package>
</struts>

package cn.interceptor;

import java.util.Map;

import org.apache.struts2.ServletActionContext;

import cn.action.LoginAction;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;

public class MyInterceptor implements Interceptor {

	private static final long serialVersionUID = 1L;

	@Override
	public void destroy() {

	}

	@Override
	public void init() {
		System.out.println("init invoked");
	}

	@Override
	public String intercept(ActionInvocation invoke) throws Exception {
		System.out.println("before");

		// 如果是LoginAction不用拦截，其他的则进行判断拦截
		if (LoginAction.class == invoke.getAction().getClass())
			return invoke.invoke();

		Map<String, Object> sessions = (Map<String, Object>) ServletActionContext.getContext().getSession();
		String username = (String) sessions.get("username");
		if (null == username || username.equals("")) {
			System.out.println("unLogin");
			return "unLogin";
		} else {
			return invoke.invoke();
		}
	}

}

package cn.bean;

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;
	}

}

package cn.base;

import java.util.Map;

import org.apache.struts2.ServletActionContext;

public class BaseAction {
	protected Map<String, Object> session = ServletActionContext.getContext().getSession();
}

package cn.action;

import cn.base.BaseAction;
import cn.bean.User;

public class LoginAction extends BaseAction{
	private User user;

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

	public User getUser() {
		return user;
	}

	public String Login() {
		if (null == user.getUsername() || user.getUsername().equals("")) {
			return "error";
		} else {
			session.put("username", user.getUsername());
			return "success";
		}

	}
}

package cn.action;

import cn.base.BaseAction;
import cn.bean.User;

public class UserAction extends BaseAction{
	private User user;

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

	public User getUser() {
		return user;
	}

	public String addUser() {
		if (null == user.getUsername() || user.getUsername().equals("")) {
			return "error";
		} else {
			session.put("username", user.getUsername());
			return "success";
		}
	}
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
	<form action="login" method="post">
		username: <input type="text" name="user.username"><br /> 
		password:<input type="text" name="user.password"><br /> 
		<input type="submit" value="submit">
	</form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
	<form action="addUser" method="post">
		username: <input type="text" name="user.username"><br /> 
		password:<input type="text" name="user.password"><br /> 
		<input type="submit" value="submit">
	</form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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>Insert title here</title>
</head>
<body>
<h3><a href="#">拦截器首页</a></h3>

</body>
</html>