我发现Mockbean可以在测试主线程中工作，但不能在新线程调用中工作，下面是我的演示代码。在新线程中第一次调用mock是工作的，但是当第二次调用demoService时，它返回null（mock不工作）

参考Jar版本mockito-core 4.11.0 JDK1.8 Junit 4 SpringBoot：1.5.22.RELEASE

/***
 * demo test case for find why mockito mock not work in new thread
 */
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = DemoApplication.class)
public class DemoApplicationTests {
    @MockBean
    protected DemoService demoService;
    /**
     * call the mock in main thread, the mock all work
     */
    @Test
    public void testNormalCase_work() {
        DemoServiceMock.mockdoSomething(demoService);
        String result = demoService.doSomething("324234");
        System.out.println("return: " + result);
        String result2 = demoService.doSomething("324234");
        System.out.println("return2: " + result);
    }
    /***
     * call the mock in new thread
     * When call the demoService in second times, it return null (mock not work)
     */
    @Test
    public void testInNewThread_notWork() {
        DemoServiceMock.mockdoSomething(demoService);
        Thread t = new Thread(new Runnable() {
            public void run() {
                //for the first time call, the mock is work
                String result = demoService.doSomething("324234");
                System.out.println("return in thread: " + result);
                //for this second time call in new thread, the mock not work and return null
                String result2 = demoService.doSomething("324234");
                System.out.println("return2 in thread: " + result2);
            }
        });
        t.start();
    }
}
public class DemoServiceMock {
    public static void mockdoSomething(DemoService demoService){
        Mockito.doReturn("mockReturnValue").when(demoService).doSomething(any());
    }
}

我发现Mockbean可以在测试主线程中工作，但不能在新线程调用中工作，下面是我的演示代码。在新线程中第一次调用mock是工作的，但是当第二次调用demoService时，它返回null（mock不工作）

参考Jar版本mockito-core 4.11.0 JDK1.8 Junit 4 SpringBoot：1.5.22.RELEASE