I'm just doing a simple lookup on a JPA entity (User) via a SLSB (UserService) as follows:         

try { result = userService.findByEmail(email); }       

catch(Throwable throwable)  { logger.warn("User ''{0}'' attempt to login failed due to: " + throwable.getMessage()); } 

When an incorrect email is entered I get a stack trace:

14:11:53,005 ERROR [org.jboss.ejb3.invocation] (http--127.0.0.1-8443-5) JBAS014134: EJB Invocation failed on component UserService for method public com.patrac.model.authenticate.User com.patrac.service.UserService.findByEmail(java.lang.String) throws java.lang.IllegalStateException,javax.persistence.PersistenceException: javax.ejb.EJBException: javax.persistence.NoResultException: No entity found for query

    at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleExceptionInOurTx(CMTTxInterceptor.java:166) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:230) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.as.ejb3.tx.CMTTxInterceptor.requiresNew(CMTTxInterceptor.java:333) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:192) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:59) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ee.component.TCCLInterceptor.processInvocation(TCCLInterceptor.java:45) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:165) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:173) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]

    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]

    at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:72) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]

    at com.patrac.service.UserService$$$view8.findByEmail(Unknown Source) [Patrac-ejb.jar:]

    at com.patrac.controller.authenticate.LoginChecker.lookupUser(LoginChecker.java:83) [classes:]

Here's the log message:

127.0.0.1-8443-5) User 'bad@email.com' attempt to login failed due to: javax.persistence.NoResultException: No entity found for query 

The logger logs the error message, so I know the exception is being caught.  Nevertheless I'm getting a stack trace.  Why is that?