springboot使用spybean单元测试时，若被spy的类中有transactional注解会出现NotAMockException

在springboot中使用spybean单元测试时，发现在被spy的类中，若加入了Transactional注解后，在测试类中定义被spy类的某个方法的返回值时，会抛出NotAMockException.

org.mockito.exceptions.misusing.NotAMockException:
Argument passed to when() is not a mock!
Example of correct stubbing:
doThrow(new RuntimeException()).when(mock).someMethod();
at com.xxx.xxx.xxxx.service.impl.SubCustomerServiceImplTest.should_have_xxx_rights_when_maximum_rc_greater_than_0(SubCustomerServiceImplTest.java:222)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:73)
at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:83)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
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.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

请问有朋友知道如何解决吗？

终于找到了问题原因，应该算是springboot的一个issue。以下是我的替代方法：

    @Before
    public void setUp() {
        /*
         * 获取原对象（非spring的代理bean），然后再进行spy，以替代直接使用spybean来spy含有transactional注解的类，
         * 防止抛出NotAMockException
         */
        SubCustomerServiceImpl subCustomerServiceUltimate = 
                AopTestUtils.getUltimateTargetObject(appContext.getBean(SubCustomerServiceImpl.class));
        customerService = spy(subCustomerServiceUltimate);
    }

参考链接：
https://github.com/spring-projects/spring-boot/issues/7033
https://github.com/igormukhin/spring-boot-issue-6871/blob/master/src/test/java/com/example/WithoutSpyBeanTest.java
https://jira.spring.io/browse/SPR-14701?redirect=false&focusedCommentId=132050
https://github.com/spring-projects/spring-framework/issues/19265