java - 测试基于注解的 RequestInterceptor

Question

我想在某些路线上这样做自定义逻辑(记录请求和响应)。基于一些研究，我决定使用 AnnotationBased RequestInterceptor。这是我的拦截器代码。

public class CustomInterceptor extends HandlerInterceptorAdapter {
@Override
public void afterCompletion(final HttpServletRequest request,
                            final HttpServletResponse response,
                            final Object handler,
                            final Exception ex) {
     if (handler != null && handler instanceof  HandlerMethod) {
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        CustomRecord annotation = AnnotationUtils.getAnnotation(handlerMethod.getMethod(), CustomRecord.class);
        if (annotation != null) {
              // Record Request and Response in a File.
        }
}

现在这个类按预期工作，但我无法对这个函数进行单元测试。

我首先想到尝试创建一个 HandlerMethod 对象，但我
没有得到任何地方。

其次，我尝试使用 PowerMokito。这是我的测试代码:

@RunWith(PowerMockRunner.class)
@PrepareForTest(CustomInterceptor.class)
@PowerMockIgnore("javax.management.*")
public class CustomInterceptorTest {
@Test
public void restAnnotationRecording_negetivecase() {
  HandlerMethod mockHandler = mock(HandlerMethod.class);
  PowerMockito.mockStatic(AnnotationUtils.class);
  when(AnnotationUtils.getAnnotation(mockHandler.getMethod(), 
       CustomRecord.class).thenReturn(null);
  // Verify file is not saved
}
 // A spy is stubbed using when(spy.foo()).then() syntax. It is safer to stub spies - - with doReturn|Throw() family of methods. More in javadocs for Mockito.spy() methodcannot be saved.
@Test
public void restAnnotationRecording_happycase() {
    HandlerMethod mockHandler = mock(HandlerMethod.class);
    PowerMockito.mockStatic(AnnotationUtils.class);
    when(AnnotationUtils.getAnnotation(mockHandler.getMethod(), CustomRecord.class).thenReturn(mockAnnotation);
    // Verify file is saved
}
}

这给出了一个错误 A spy is stubbed using when(spy.foo()).then() 语法。使用 doReturn|Throw() 系列方法 stub spy 更安全。

我想检查是否有任何方法来测试拦截器。我是Java新手，感谢您的帮助。

Answer 1

您可以轻松创建自己的HandlerMethod没有 mock 。有一个constructor接受一个对象( Controller )和一个Method ( Controller 方法)。获得 Method 的最简单方法就是直接调用Class.getMethod() .您要做的只是创建一个虚拟 Controller 类，然后使用该类来获取方法。例如

class TestController {
    @Custom
    public void testMethod() {}
}

Method method = TestController.class.getMethod("testMethod");
TestController controller = new TestController();
HandlerMethod handlerMethod = new HandlerMethod(controller, method);

Custom annotation = handlerMethod.getMethodAnnotation(Custom.class);

就这么容易。下面是一个完整的测试。

public class HandlerInterceptorTest {

    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.RUNTIME)
    private @interface Custom {
    }

    private static class MyHandlerInterceptor implements HandlerInterceptor {

        @Override
        public boolean preHandle(HttpServletRequest req, HttpServletResponse res, Object handler) {
            if (handler instanceof HandlerMethod) {
                HandlerMethod handlerMethod = (HandlerMethod) handler;
                Custom annotation = handlerMethod.getMethodAnnotation(Custom.class);
                if (annotation != null) {
                    return true;
                }
            }
            return false;
        }
    }

    private static class TestController {
        @Custom
        public void testMethodWithAnnotation() {}

        public void testMethodWithoutAnnotation() {}
    }

    @Test
    public void testMethodWithAnnotation() throws Exception {
        Method method = TestController.class.getMethod("testMethodWithAnnotation");
        TestController controller = new TestController();
        HandlerMethod handlerMethod = new HandlerMethod(controller, method);

        MyHandlerInterceptor interceptor = new MyHandlerInterceptor();
        boolean result = interceptor.preHandle(null, null, handlerMethod);

        assertTrue(result);
    }

    @Test
    public void testMethodWithoutAnnotation() throws Exception {
        Method method = TestController.class.getMethod("testMethodWithoutAnnotation");
        TestController controller = new TestController();
        HandlerMethod handlerMethod = new HandlerMethod(controller, method);

        MyHandlerInterceptor interceptor = new MyHandlerInterceptor();
        boolean result = interceptor.preHandle(null, null, handlerMethod);

        assertFalse(result);
    }
}