我有一个类ClassA，它从org.apache.struts.actions.DispatchAction扩展了DispatchAction类。我已经为ClassA编写了JUnit代码覆盖测试，但是每当我尝试运行测试用例时，我总是得到这些错误，但是如果我从ClassA中删除extends DispatchAction，测试将正常运行，没有任何错误，但是显然我的应用程序将无法运行ClassA

public class ClassA extends DispatchAction {
//some methods and other code
}

测试类别A

@RunWith(Junit4.class)
public class TestClassA {
@InjectMocks
ClassA objA;
/* mock some objects here */
@Before
public void setUp()
{
MockitoAnnotations.openMocks(this);
}
@Test
public void methodToTest()
{
//Coverage code
objA.methodA();
}
}

这是我运行这个测试用例时得到的堆栈跟踪（当我在类ClassA中保留“extends DispatchAction”时）

java.lang.ExceptionInInitializerError at 
java.lang.J9VMInternals.ensureError(J9VMInternals.java:148) at 
java.lang.J9VMInternals.recordInitializationFailure(J9VMInternals.java:137) at 
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at 
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:83) at 
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:57) at 
java.lang.reflect.Constructor.newInstance(Constructor.java:437) at 
org.junit.runners.BlockJUnit4ClassRunner.createTest(BlockJUnit4ClassRunner.java:217) at 
org.junit.runners.BlockJUnit4ClassRunner$1.runReflectiveCall(BlockJUnit4ClassRunner.java:266) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at 
org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:263) at 
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) at 
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) at 
org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at 
org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at 
org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at 
org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at 
org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at 
org.junit.runners.ParentRunner.run(ParentRunner.java:363) at 
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41) at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541) at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463) at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209) 

Caused by: java.lang.NullPointerException at 
org.apache.struts.util.MessageResources.getMessageResources(MessageResources.java:577) at 
org.apache.struts.actions.DispatchAction.<clinit>(DispatchAction.java:153) ... 22 more

现在，如果我从类ClassA中删除“extends DispatchAction”，它将运行并覆盖测试用例中的预期行，而不会出现任何问题，但我的应用程序将无法按预期工作。
我试着搜索如何解决所有这些错误，但我找不到任何可能有帮助的东西。