Question

我将Netbeans从7.3更新到8.01，将Glassfish从4.0更新到4.1。现在我的项目中有这个例外。为什么？Session不是null但我有nullpointerexception。我哪里做错了？感谢

12|public class LogoutServlet extends HttpServlet {
13|
14|@Override
15|protected void doGet(HttpServletRequest request,HttpServletResponse response)
16|        throws ServletException,IOException{
17|    
18|    HttpSession session=request.getSession();
19|    if(session!=null)
20|        session.invalidate();
21|    response.sendRedirect("index.jsp");
22| }//doGet
23|
24|}//LogoutServlet

错误代码：

Session event listener threw exception
java.lang.NullPointerException
at org.jboss.weld.servlet.WeldTerminalListener.getSessionContext(WeldTerminalListener.java:65)
at org.jboss.weld.servlet.WeldTerminalListener.sessionDestroyed(WeldTerminalListener.java:57)
at org.apache.catalina.session.StandardSession.expire(StandardSession.java:910)
at org.apache.catalina.session.StandardSession.expire(StandardSession.java:854)
at org.apache.catalina.session.StandardSession.expire(StandardSession.java:842)
at org.apache.catalina.session.StandardSession.invalidate(StandardSession.java:1603)
at  org.apache.catalina.session.StandardSessionFacade.invalidate(StandardSessionFacade.java:204)
at store.web.LogoutServlet.doGet(LogoutServlet.java:20)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:724)

Answer 1

Netbeans 8.1和Glassfish Open Source Edition 4.1（版本13）上的同样问题。您必须通过在beans.xml文件夹中创建或修改./WEB-INF文件来禁用CDI：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
       http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
       bean-discovery-mode="none">
</beans>

bean-discovery-mode设置为none。

更多信息here。

Answer 2

即使您没有将bean注入到您的应用程序中，也可以使用以下内容创建 beans.xml 文件（无需在其中声明任何bean） em>“src / main / webapp / WEB-INF /”一次为我解决了这个问题：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
</beans>

Glassfish 4.1错误：session.invalidate nullpointer异常

2 个答案: