尽管引发了预期的异常，但jUnit测试失败

这是我的应用程序中的测试方式：

@Test (expected = UniqueFieldValueConstraintViolationException.class)
    public void testName() {
       Branch b1 = new Branch("tetsname","Test 234","06:00-17:00","098144658");
       Branch b2 = new Branch("tetsname","Test 234","06:00-17:00","098144658");
       db.store(b1);
       db.store(b2);
       db.commit();
     }

尽管抛出了异常，但此测试失败：

com.db4o.constraints.UniqueFieldValueConstraintViolationException：class：dataModel.Branch field：pNumber at
com.db4o.constraints.UniqueFieldValueConstraint $ 1.ensureSingleOccurence（UniqueFieldValueConstraint.java:66）at com.db4o.constraints.UniqueFieldValueConstraint $ 1.onEvent（UniqueFieldValueConstraint.java:97）at com.db4o.internal.events.Event4Impl.trigger（Event4Impl . java：78）at com.db4o.internal.events.EventRegistryImpl $ 4.run（EventRegistryImpl.java:123）at com.db4o.foundation.DynamicVariable.with（DynamicVariable.java:54）at com.db4o.internal.InCallback . 运行（InCallback.java:24）com.db4o.internal.events.EventRegistryImpl.withExceptionHandlingInCallback（EventRegistryImpl.java:279）at com.db4o.internal.events.EventRegistryImpl.commitOnStarted（EventRegistryImpl.java:121）at com.db4o .internal.LocalTransaction.dispatchCommittingCallback（LocalTransaction.java:89）at com.db4o.internal.LocalTransaction.commit（LocalTransaction.java:66）at com.db4o.internal.LocalTransaction.commit（LocalTransaction.java:59）at com . db4o.internal.LocalObjectContainer.commitTransaction（LocalObjectContainer.java:689）at at com.db4o.internal.LocalObjectContainer.close2（LocalObjectContainer.java:94）at com.db4o.internal.ObjectContainerBase.close1（ObjectContainerBase.java:361）at com.db4o.internal.ObjectContainerBase.close（ObjectContainerBase.java:344） at tests.BranchTests.cleanUp（BranchTests.java:127）at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）at sun.reflect.NativeMethodAccessorImpl.invoke（Unknown Source）at sun.reflect.DelegatingMethodAccessorImpl.invoke（Unknown Source）at at java.lang.reflect.Method.invoke（未知来源）org.junit.runners.model.FrameworkMethod $ 1.runReflectiveCall（FrameworkMethod.java:47）at org.junit.internal.runners.model.ReflectiveCallable.run（ReflectiveCallable . java：12）org.junit.runners.model.FrameworkMethod.invokeExplosively（FrameworkMethod.java:44）atg.junit.runners.runners.statements.RunAfters.evaluate（RunAfters.java:33）org.junit.runners .parentRunner.runLeaf（ParentRunner.java:271）位于org.junit.runners.BlockJUnit4ClassRunner.runChild（BlockJUnit4Class） Runner.java:70）org.junit.runners.BlockJUnit4ClassRunner.runChild（BlockJUnit4ClassRunner.java:50）org.junit.runners.ParentRunner $ 3.run（ParentRunner.java:238）org.junit.runners.ParentRunner $ 1 .schedule（ParentRunner.java:63）org.junit.runners.ParentRunner.runChildren（ParentRunner.java:236）org.junit.runners.ParentRunner.access $ 000（ParentRunner.java:53）org.junit.runners org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run上的.garentRunner $ 2.evaluate（ParentRunner.java:229）org.junit.runners.ParentRunner.run（ParentRunner.java：309）（JUnit4TestReference.java： 50）org.eclipse.jdt.internal.junit.runner.TestExecution.run（TestExecution.java:38）org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:467）at org位于org.eclipse.jdt的org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run（RemoteTestRunner.java:390）的.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:683） .internal.junit.runner.RemoteTes tRunner.main（RemoteTestRunner.java:197）

我该如何避免这种行为？