J2EE JPA missing descriptor

qiqimon5566

目前正在學習jpa當中
而不知道為何 出現了 missing descriptor 這個問題

嘗試找了好久的資料 發現很多人有這問題 可是好像只有我solve不到 xDD

所以 我還是上來論壇發問下 》。《

1. public User userAuthentication(String id, String password) throws CinemaException {
   
2.         try {
   
3.             Query query = em.createNativeQuery("SELECT * FROM User WHERE USER_PASSWORD = MD5('" + password + "') AND USER_ID = '" + id + "'", User.class);
   
4.             return (User)query.getSingleResult();
   
5.         } catch (NoResultException ex) {
   
6.             return null;
   
7.         }
   
8.     }

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經過測試之後 我發現問題的起因 應該是 return (User)query.getSingleResult(); 這一句
可是卻不知道要怎樣solve
因為這問題有點奇怪 = = 每當我第一次開netbean deploy run都不會有問題
之後 大概save re-deploy 1次 或者幾次 就會出現missing descriptor的問題
error 如下

1. WARNING: Local Exception Stack:
   
2. Exception [EclipseLink-6007] (Eclipse Persistence Services - 2.2.0.v20110202-r8913): org.eclipse.persistence.exceptions.QueryException
   
3. Exception Description: Missing descriptor for [class model.User].
   
4. Query: ReadAllQuery(referenceClass=User sql="SELECT * FROM User WHERE USER_PASSWORD = MD5('11111111') AND USER_ID = 'qiqimon5566'")
   
5.         at org.eclipse.persistence.exceptions.QueryException.descriptorIsMissing(QueryException.java:452)
   
6.         at org.eclipse.persistence.queries.ObjectLevelReadQuery.checkDescriptor(ObjectLevelReadQuery.java:748)
   
7.         at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:729)
   
8.         at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1040)
   
9.         at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:383)
   
10.         at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1126)
    
11.         at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2842)
    
12.         at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1521)
    
13.         at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1503)
    
14.         at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1477)
    
15.         at org.eclipse.persistence.internal.jpa.EJBQueryImpl.executeReadQuery(EJBQueryImpl.java:484)
    
16.         at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getSingleResult(EJBQueryImpl.java:772)
    
17.         at model.Implementation.userAuthentication(Implementation.java:87)
    
18.         at controller.Login.processRequest(Login.java:67)
    
19.         at controller.Login.doPost(Login.java:115)
    
20.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:755)
    
21.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    
22.         at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
    
23.         at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
    
24.         at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    
25.         at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    
26.         at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    
27.         at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
    
28.         at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
    
29.         at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
    
30.         at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326)
    
31.         at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227)
    
32.         at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:170)
    
33.         at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822)
    
34.         at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719)
    
35.         at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013)
    
36.         at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
    
37.         at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    
38.         at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    
39.         at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    
40.         at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    
41.         at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    
42.         at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    
43.         at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    
44.         at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    
45.         at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    
46.         at java.lang.Thread.run(Thread.java:662)
    

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qiqimon5566

只要一重開glassfish 這個exception就會不見掉 = =?