Struts2的攔截器溢出異常

Question

我正在使用的Struts2 + Spring + Hibernate的Web應用程序登錄模塊，並且我要強制用戶登錄，如果他們想瀏覽低谷的網站。

我有一個LoginInterceptor

public class LoginInterceptor implements Interceptor { 

public LoginInterceptor() { 
} 

public void destroy() { 
    System.out.println("LoginInterceptor destroy() is called..."); 
} 

public void init() { 
    System.out.println("LoginInterceptor init() is called..."); 
} 

public String intercept(ActionInvocation actionInvocation) throws Exception { 

    final ActionContext context = actionInvocation.getInvocationContext(); 
    HttpServletRequest request = (HttpServletRequest) context.get(ServletActionContext.HTTP_REQUEST); 
    HttpSession session = request.getSession(true); 

    //Code 

    try { 

     Users userObj = (Users) session.getAttribute("userObj"); 

     if (userObj == null) { 
      System.out.println("if from LoginInterceptor"); 
      return "noLogin"; 
     } 

    } catch (Exception e) { 
     Logger.getLogger(LoginInterceptor.class.getName()).log(Level.INFO, "message", e); 
    } 

    //Invoke action 
    String result = actionInvocation.invoke(); 

    return result; 
} 
} 

我在struts.xml

<interceptors> 

     <interceptor name="myLocale" class="com.deveto.struts.interceptors.LocaleInterceptor"/> 
     <interceptor name="login" class="com.deveto.struts.interceptors.LoginInterceptor"/> 
     <interceptor name="access" class="com.deveto.struts.interceptors.AccessInterceptor"/> 

     <interceptor-stack name="defaultStack"> 
      <interceptor-ref name="myLocale"/> 
      <interceptor-ref name="login"/> 
      <interceptor-ref name="exception"/> 
      <interceptor-ref name="alias"/> 
      <interceptor-ref name="prepare"/> 
      <interceptor-ref name="i18n"/> 
      <interceptor-ref name="chain"/> 
      <interceptor-ref name="debugging"/> 
      <interceptor-ref name="profiling"/> 
      <interceptor-ref name="fileUpload"/> 
      <interceptor-ref name="checkbox"/> 
      <interceptor-ref name="params"> 
       <param name="excludeParams">dojo\..*</param> 
      </interceptor-ref> 
      <interceptor-ref name="conversionError"/> 
      <interceptor-ref name="validation"> 
       <param name="excludeMethods">input,back,cancel,browse</param> 
      </interceptor-ref> 
      <interceptor-ref name="workflow"> 
       <param name="excludeMethods">input,back,cancel,browse</param> 
      </interceptor-ref> 
     </interceptor-stack> 
    </interceptors> 

    <default-interceptor-ref name="defaultStack"/> 

    <global-results> 
     <result name="noLogin" type="redirectAction">show-login</result> 
     <result name="noAccess" type="redirectAction">access-required</result> 
    </global-results> 

    <action 
     name="show-login" 
     class="com.deveto.struts.actions.UsersAction" > 
     <interceptor-ref name="defaultStack"/> 
     <result name="success" type="tiles">tiles.login</result> 
    </action> 

但是當我運行該項目，我有一個溢出異常，在堆棧跟蹤我什麼都沒有，但Mozilla的告訴我即：

 The page isn't redirecting properly 

     Firefox has detected that the server is redirecting the request for this address in a way that will never complete. 

和

System.out.println("if from LoginInterceptor"); 

重複幾次。我不明白爲什麼，但我有更多的攔截器，以及除此之外的其他作品。

Answer 1

當你的LoginInterceptor返回其noLogin結果它重定向，這再次被LoginInterceptor攔截，這將其變成一個無盡的重定向循環。

所以，你必須從你的LoginInterceptor，例如被攔截排除您的show-login

定義兩個攔截器堆棧，並與LoginInterceptor設置一個爲默認：

<interceptor-stack name="defaultStack"> 
    ... same as in your question ... 
</interceptor-stack> 

<interceptor-stack name="noLoginStack"> 
    ... same as in your question but *without* the LoginInterceptor ... 
</interceptor-stack> 

<default-interceptor-ref name="defaultStack"/> 

再來說show-login動作而已，使用noLoginStack：

<action name="show-login" 
    ... > 
    <interceptor-ref name="noLoginStack"/> 
    ... 
</action> 

Answer 2

何不你用Spring Security來做那件事嗎？ 配置非常簡單，它可以與Struts2完美配合。 剛剛從那裏開始：http://static.springsource.org/spring-security/site/tutorial.html或有：http://www.mularien.com/blog/2008/07/07/5-minute-guide-to-spring-security/