使用OpenJPA，可以向数据库中插入数据，但一读数据就出错！

我执行了一个插入操作，使用EntityManager.persist()，但是当我紧接着就查询的时候，遇到了如下的错误：
这真是太奇怪了，PayOut这个类明明是刚刚插入过数据的！
<openjpa-1.1.0-r422266:657916 nonfatal user error> org.apache.openjpa.persistence.ArgumentException: An error occurred while parsing the query filter "SELECT i FROM PayOut i". Error message: The name "PayOut" is not a recognized entity or identifier. Known entity names: []
org.apache.openjpa.kernel.exps.AbstractExpressionBuilder.parseException(AbstractExpressionBuilder.java:118)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getClassMetaData(JPQLExpressionBuilder.java:180)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.resolveClassMetaData(JPQLExpressionBuilder.java:150)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:225)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:195)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateType(JPQLExpressionBuilder.java:188)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.access$600(JPQLExpressionBuilder.java:69)
org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder$ParsedJPQL.populate(JPQLExpressionBuilder.java:1754)
org.apache.openjpa.kernel.jpql.JPQLParser.populate(JPQLParser.java:56)
org.apache.openjpa.kernel.ExpressionStoreQuery.populateFromCompilation(ExpressionStoreQuery.java:153)
org.apache.openjpa.kernel.QueryImpl.newCompilation(QueryImpl.java:657)
org.apache.openjpa.kernel.QueryImpl.compilationFromCache(QueryImpl.java:638)
org.apache.openjpa.kernel.QueryImpl.compileForCompilation(QueryImpl.java:604)
org.apache.openjpa.kernel.QueryImpl.compileForExecutor(QueryImpl.java:666)
org.apache.openjpa.kernel.QueryImpl.getOperation(QueryImpl.java:1486)
org.apache.openjpa.kernel.DelegatingQuery.getOperation(DelegatingQuery.java:123)
org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:227)
org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:277)
com.sun.tutorial.javaee.ejb.DatabaseServiceBean.getAll(DatabaseServiceBean.java:64)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112)
org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166)
org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79)
org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:304)
org.jboss.ejb3.remoting.IsLocalInterceptor.invokeLocal(IsLocalInterceptor.java:81)
org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:72)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessRemoteProxy.invoke(StatelessRemoteProxy.java:107)
$Proxy226.getAll(Unknown Source)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:301)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:198)
$Proxy229.getAll(Unknown Source)
org.edu.jlu.ljy.finace.web.servlet.PayoutController.show(PayoutController.java:97)
org.edu.jlu.ljy.finace.web.servlet.PayoutController.insert(PayoutController.java:92)
org.edu.jlu.ljy.finace.web.servlet.PayoutController.handleRequest(PayoutController.java:68)
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:476)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:431)
javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)