【发布时间】：2011-12-31 07:59:27
【问题描述】：
在我的 JSF 应用程序中，成功登录后，我将导航到我的应用程序主页，其中有一个 Logout 链接。
这里是注销链接的相关html。
<div id="top_white">
<div style="float: right"><tr:form><tr:commandLink id="logout" action="#{Controller.Logout}"><img alt="logout" src="../../images/logout.gif"/></tr:commandLink></tr:form></div>
</div>
这是我的Controller sessionscoped
public class Controller {
private static Logger LOGGER = Logger.getLogger(Controller.class);
public Controller() {
req = (HttpServletRequest)FacesContext.getCurrentInstance().getExternalContext().getRequest();
session = req.getSession(false);
String userid = session.getAttribute("userid").toString();
if(List == null){
List = new ArrayList<List>();
List = new DAO().loadListByid(Long.valueOf(userid));
LOGGER.debug("successfully loaded the list for the user");
}
}
private long Username;
private String Password=null;
HttpServletRequest req;
HttpSession session;
private List<List> List=null;
// getter and setters
public String Logout(){
session.invalidate();
LOGGER.debug("In LogOut");
return "loggedout";
}
}
在构造函数中，我检查会话中的用户 ID 并将特定列表加载给用户。
我还有一个ServletFilter，它会检查每个会话中的某个 id。如果找不到，它会重定向到 InvalidUser 页面。我的过滤器映射到 /faces/jsp/*，以便检查 jsp 文件夹中的所有 jsp会话中的 id。
这是我的过滤器的doFilter 方法
public void doFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
LOGGER.debug("In doFilter");
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
HttpSession session = request.getSession(false);
LOGGER.debug("request:" + request.getRequestURL().toString());
try{
if (session.getAttribute("id") != null) {
LOGGER.debug("id found:" + session.getAttribute("id"));
chain.doFilter(req, res); // id found, so just continue request.
}
}catch(NullPointerException e){
LOGGER.debug("No id found Exception: ", e);
response.sendRedirect(properties.getProperty(INVALID_USER_REDIRECTURL, true)); // No id found, so redirect to Invalid user page.
}
}
我还添加了一个PhaseListener 来调试来自here 的JSF 生命周期。
第一次加载页面时，我看到以下服务器日志，其中只有 JSF 生命周期的第一阶段和最后阶段
["http-bio-8090"-exec-114] DEBUG SessionFilter - In doFilter
["http-bio-8090"-exec-114] DEBUG SessionFilter - request:http://my homepageurl
["http-bio-8090"-exec-114] DEBUG SessionFilter - id found
["http-bio-8090"-exec-114] ERROR org.apache.myfaces.config.FacesConfigurator - Configuration objects do not support clean-up. Update aborted
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE RESTORE_VIEW(1)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE RESTORE_VIEW(1)
["http-bio-8090"-exec-114] DEBUG org.apache.myfaces.lifecycle.LifecycleImpl - exiting from lifecycle.execute in RESTORE_VIEW(1) because getRenderResponse is true from one of the after listeners
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE RENDER_RESPONSE(6)
["http-bio-8090"-exec-114] INFO org.apache.myfaces.config.annotation.DefaultLifecycleProviderFactory - Using LifecycleProvider org.apache.myfaces.config.annotation.AllAnnotationLifecycleProvider
["http-bio-8090"-exec-114] DEBUG Controller - id found in controller
["http-bio-8090"-exec-114] DEBUG DAOProperties - dao.properties loaded successfully
["http-bio-8090"-exec-114] DEBUG SvrConnection - In JNDI
["http-bio-8090"-exec-114] DEBUG DAO - Successfully connected to database
["http-bio-8090"-exec-114] DEBUG DAO - connection closed
["http-bio-8090"-exec-114] DEBUG Controller - successfully loaded the list for the user
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE RENDER_RESPONSE(6)
上面的日志是预期的，因为没有表单提交类型的东西。所以只列出了第一阶段和最后阶段。
但是当我点击我在这篇文章顶部提到的Logout commandLink 时，真正的问题来了。
点击Logout链接后，这里是服务器日志。
["http-bio-8090"-exec-114] DEBUG SessionFilter - In doFilter
["http-bio-8090"-exec-114] DEBUG SessionFilter - request:http://my homepage url
["http-bio-8090"-exec-114] DEBUG SessionFilter - appid found
["http-bio-8090"-exec-114] ERROR org.apache.myfaces.config.FacesConfigurator - Configuration objects do not support clean-up. Update aborted
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE RESTORE_VIEW(1)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE RESTORE_VIEW(1)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE APPLY_REQUEST_VALUES(2)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE APPLY_REQUEST_VALUES(2)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE PROCESS_VALIDATIONS(3)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE PROCESS_VALIDATIONS(3)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE UPDATE_MODEL_VALUES(4)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE UPDATE_MODEL_VALUES(4)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE INVOKE_APPLICATION(5)
["http-bio-8090"-exec-114] DEBUG Controller - In LogOut
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE INVOKE_APPLICATION(5)
["http-bio-8090"-exec-114] DEBUG org.apache.myfaces.lifecycle.LifecycleImpl - exiting from lifecycle.execute in INVOKE_APPLICATION(5) because getRenderResponse is true from one of the after listeners
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - START PHASE RENDER_RESPONSE(6)
["http-bio-8090"-exec-114] DEBUG LifeCycleListener - END PHASE RENDER_RESPONSE(6)
["http-bio-8090"-exec-116] DEBUG SessionFilter - In doFilter
["http-bio-8090"-exec-116] DEBUG SessionFilter - request:http://my homepage url
["http-bio-8090"-exec-116] DEBUG SessionFilter - No id found Exception:
java.lang.NullPointerException
从上面的日志中，正如预期的那样，我的操作方法在 INVOKE_APPLICATION 中被调用，并且我的控制器的 Logout() 方法被调用，会话无效并返回字符串 loggedout。
我在faces-config.xml中有如下导航规则
<navigation-rule>
<from-view-id>/jsp/Services.jsp</from-view-id>
<navigation-case>
<from-outcome>loggedout</from-outcome>
<to-view-id>/others/Logout.jsp</to-view-id>
</navigation-case>
</navigation-rule>
但是这个navigation-rule 没有执行。相反，在RENDER_RESPONSE 阶段，它会尝试重新加载我的同一个主页 url。显然它在会话中没有id，这会导致抛出NullPointerException。
我在上面给出的相应文件夹中有 jsp。我使用的是 JSF 1.2 和 myFaces 1.2.9。
1)为什么navigation-case不执行？
2)为什么又重新加载了我的主页url？
请有人帮忙。
【问题讨论】：