在struts2中使用拦截器（Interceptor）控制登录和权限

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转载最新推荐文章于 2026-05-20 07:53:37 发布 909 阅读 AI 写同款· GEO 优化 ›

[quote="dengyin2000"]在jsp servlet中我们通常使用Servlet Filter控制用户是否登入，是否有权限转到某个页面。在struts2中我们应该会想到他的拦截器（Interceptor）， Interceptor在struts2中起着非常重要的作用。很多struts2中的功能都是使用Interceptor实现的。

需求：简单的登入界面，让用户输入用户名、密码、记住密码（remember me）。如果用户选中remember me的话，下次就不需要再登入了（使用cookie实现，用需要点击logout取消remeber me功能）。如果用户起始输入的地址不是登入页面的话，在用户登入之后需要转到用户输入的起始地址。

我们先看看LoginInterceptor.java [code] package com.javaeye.dengyin2000.wallet.interceptor;

import java.util.Map;

import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang.StringUtils; import org.apache.struts2.StrutsStatics;

import com.javaeye.dengyin2000.wallet.dao.UserDAO; import com.javaeye.dengyin2000.wallet.dao.UserNotFoundException; import com.javaeye.dengyin2000.wallet.domains.User; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.ActionInvocation; import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class LoginInterceptor extends AbstractInterceptor { public static final String USER_SESSION_KEY="wallet.session.user"; public static final String COOKIE_REMEMBERME_KEY="wallet.cookie.rememberme"; public static final String GOING_TO_URL_KEY="GOING_TO"; private UserDAO userDao;

@Override public String intercept(ActionInvocation invocation) throws Exception { ActionContext actionContext = invocation.getInvocationContext(); HttpServletRequest request= (HttpServletRequest) actionContext.get(StrutsStatics.HTTP_REQUEST); Map session = actionContext.getSession(); if (session != null && session.get(USER_SESSION_KEY) != null){ return invocation.invoke(); } Cookie[] cookies = request.getCookies(); if (cookies!=null) { for (Cookie cookie : cookies) { if (COOKIE_REMEMBERME_KEY.equals(cookie.getName())) { String value = cookie.getValue(); if (StringUtils.isNotBlank(value)) { String[] split = value.split("=="); String userName = split[0]; String password = split[1]; try { User user = userDao .attemptLogin(userName, password); session.put(USER_SESSION_KEY, user); } catch (UserNotFoundException e) { setGoingToURL(session, invocation); return "login"; } } else { setGoingToURL(session, invocation); return "login"; } return invocation.invoke(); } } } setGoingToURL(session, invocation); return "login"; }

private void setGoingToURL(Map session, ActionInvocation invocation){ String url = ""; String namespace = invocation.getProxy().getNamespace(); if (StringUtils.isNotBlank(namespace) && !namespace.equals("/")){ url = url + namespace; } String actionName = invocation.getProxy().getActionName(); if (StringUtils.isNotBlank(actionName)){ url = url + "/" + actionName + ".action"; } session.put(GOING_TO_URL_KEY, url); } public UserDAO getUserDao() { return userDao; }

public void setUserDao(UserDAO userDao) { this.userDao = userDao; }

}[/code]

首先判断session中有没有用户信息，如果有的话继续，如果没有的话，检查cookie中有没有rememberme的值，如果有的话，用==分割，取得用户名密码进行登入。如果没有这个用户的话，记录下request的action地址然后转到登入页面。如果验证有这个用户，则继续下面的interceptor。如果cookie中没有信息的话，则记录request的action地址然后转到登入页面。以上就是LoginInterceptor的全部代码。

下面我们看看struts.xml

[code]<?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="default" extends="struts-default"> <interceptors> <interceptor name="loginInterceptor" class="loginInterceptor"></interceptor> <interceptor-stack name="loginDefaultStack"> <interceptor-ref name="loginInterceptor"></interceptor-ref> <interceptor-ref name="defaultStack"></interceptor-ref> </interceptor-stack> </interceptors> <default-interceptor-ref name="loginDefaultStack"></default-interceptor-ref> <global-results> <result name="login" type="redirect">/login.jsp</result> </global-results> <action name="index" class="indexAction"> <result>/index.jsp</result> </action> <action name="logout" class="logoutAction"></action> <action name="login" class="loginAction" method="login"> <result type="redirect">${goingToURL}</result> <result name="input">/login.jsp</result> <interceptor-ref name="defaultStack"></interceptor-ref> </action> <action name="register" class="registerAction"> <result type="redirect">/login.jsp</result> <result name="input">/register.jsp</result> <interceptor-ref name="defaultStack"></interceptor-ref> </action> </package> </struts>[/code]

我们是使用的默认的interceptor stack是loginInterceptor，如果你需要让不登入的用户也能访问的话，你需要配置你的action使用defaultStack。我们这里的login, register使用的就是defaultStack。这里要注意的是success的result是我们用LoginInterceptor设过来的值。这样我们就能够转到用户输入的起始页面。下面我们再来看看login.jsp 和 loginAction

[code]<%@taglib prefix="s" uri="/struts-tags" %> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Wallet-Login</title> </head> <body> <h2>Login</h2> <s:actionmessage/> <s:actionerror/> <s:form action="login" method="post" validate="false" theme="xhtml"> <s:textfield name="loginName" label="Username"></s:textfield><br/> <s:password name="password" label="Password"></s:password><br/> <s:checkbox label="Remember Me" name="rememberMe"></s:checkbox> <s:submit value="%{'Login'}"></s:submit> </s:form> <a href="register.jsp">Register</a> </body> </html>[/code]

[code]package com.javaeye.dengyin2000.wallet.actions;

import java.util.Map;

import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils; import org.apache.struts2.interceptor.CookiesAware; import org.apache.struts2.interceptor.ServletRequestAware; import org.apache.struts2.interceptor.ServletResponseAware; import org.apache.struts2.interceptor.SessionAware;

import com.javaeye.dengyin2000.wallet.dao.UserDAO; import com.javaeye.dengyin2000.wallet.dao.UserNotFoundException; import com.javaeye.dengyin2000.wallet.domains.User; import com.javaeye.dengyin2000.wallet.interceptor.LoginInterceptor; import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport implements ServletResponseAware, ServletRequestAware, SessionAware, CookiesAware{

private UserDAO userDao; private String loginName; private String password; private boolean rememberMe; private HttpServletResponse response; private HttpServletRequest request; private Map session; private Map cookies; private String goingToURL; public String getGoingToURL() { return goingToURL; } public void setGoingToURL(String goingToURL) { this.goingToURL = goingToURL; } public boolean isRememberMe() { return rememberMe; } public void setRememberMe(boolean rememberMe) { this.rememberMe = rememberMe; } public String getLoginName() { return loginName; } public void setLoginName(String loginName) { this.loginName = loginName; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String login()throws Exception{ try { User user = userDao.attemptLogin(loginName, password); if (rememberMe){ Cookie cookie = new Cookie(LoginInterceptor.COOKIE_REMEMBERME_KEY, user.getLoginName() + "==" + user.getPassword()); cookie.setMaxAge(60 * 60 * 24 * 14); response.addCookie(cookie); } session.put(LoginInterceptor.USER_SESSION_KEY, user); String goingToURL = (String) session.get(LoginInterceptor.GOING_TO_URL_KEY); if (StringUtils.isNotBlank(goingToURL)){ setGoingToURL(goingToURL); session.remove(LoginInterceptor.GOING_TO_URL_KEY); }else{ setGoingToURL("index.action"); } return SUCCESS; } catch (UserNotFoundException e) { addActionMessage("user name or password is not corrected."); return INPUT; } } public UserDAO getUserDao() { return userDao; } public void setUserDao(UserDAO userDao) { this.userDao = userDao; } public void setServletResponse(HttpServletResponse response) { this.response = response; } public void setServletRequest(HttpServletRequest request) { this.request = request; } public void setSession(Map session) { this.session = session; } public void setCookiesMap(Map cookies) { this.cookies = cookies; } } [/code]

差不多就是这么多代码了。最后看看logoutAction

[code]package com.javaeye.dengyin2000.wallet.actions;

import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession;

import org.apache.struts2.interceptor.ServletRequestAware; import org.apache.struts2.interceptor.ServletResponseAware;

import com.javaeye.dengyin2000.wallet.interceptor.LoginInterceptor; import com.opensymphony.xwork2.ActionSupport;

public class LogoutAction extends ActionSupport implements ServletRequestAware , ServletResponseAware{

private HttpServletRequest request; private HttpServletResponse response;

public String execute() throws Exception{ HttpSession session = request.getSession(false); if (session!=null) session.removeAttribute(LoginInterceptor.USER_SESSION_KEY); Cookie[] cookies = request.getCookies(); if (cookies!=null) { for (Cookie cookie : cookies) { if (LoginInterceptor.COOKIE_REMEMBERME_KEY.equals(cookie .getName())) { cookie.setValue(""); cookie.setMaxAge(0); response.addCookie(cookie); return "login"; } } } return "login"; }

public void setServletRequest(HttpServletRequest request) { this.request = request; }

public void setServletResponse(HttpServletResponse response) { this.response = response; }

}[/code]

这里需要注意的是需要把cookie也清理下。

applicationContext-struts.xml [code]<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans>   <bean id="indexAction" class="com.javaeye.dengyin2000.wallet.actions.IndexAction" singleton="false"></bean> <bean id="loginAction" class="com.javaeye.dengyin2000.wallet.actions.LoginAction" singleton="false"> <property name="userDao" ref="userDao" /> </bean> <bean id="logoutAction" class="com.javaeye.dengyin2000.wallet.actions.LogoutAction" singleton="false"></bean> <bean id="registerAction" class="com.javaeye.dengyin2000.wallet.actions.RegisterAction" singleton="false"></bean>  <bean id="loginInterceptor" class="com.javaeye.dengyin2000.wallet.interceptor.LoginInterceptor"> <property name="userDao" ref="userDao" /> </bean> <bean id="userDao" class="com.javaeye.dengyin2000.wallet.dao.UserDAOImpl"> </bean> </beans>[/code]

参考：http://www.vitarara.org/cms/struts_2_cookbook/creating_a_login_interceptor[/quote]

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