Struts2中使用拦截器（Interceptor）控制登录和权限

        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。

Java代码:LoginInterceptor.java

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;   
    }   
  }  

 

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

XML代码: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>   
    <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>  

 

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

Jsp代码：login.jsp

<%@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>  

<%@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>

 

Java代码：LoginAction.java

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;   
    }   
}  

 

这里需要注意的是需要把cookie也清理下。

applicationContext-struts.xml

<?xml version="1.0" encoding="UTF-8"?>   
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">   
       
<beans>   
    <!-- Example of SAF2 action instantiated by Spring -->   
    <!-- bean id="helloWorldAction" class="tutorial.HelloWorldAction" singleton="false" />   
     -->   
     <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>   
        
     <!-- the following is struts2 interceptors -->   
     <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>