Mockito.doNothing（）不断返回空指针异常

debugcn 发表于 Dev

斯蒂芬·库里3093

我知道我不应该测试像这样的void方法，但是到目前为止，我只是通过一个简单的示例来测试Mockito.doNothing（）。

我的服务班级：

@Service
public class Service{
    @Autowired
    private Consumer<String, String> kafkaConsumer;

    public void clearSubscribtions(){
        kafkaConsumer.unsubscribe();
    }
}

我的测试班：

 @MockBean
 private Consumer<String, String> kafkaConsumer;

 @Test
 public void testClearSubscriptions() {
     Service service = new Service();

     Mockito.doNothing().when(kafkaConsumer).unsubscribe();
     service.clearSubscriptions();
 }

测试不断失败，并出现空指针异常。当我对其进行调试时，它将进入服务类的clearSubscription方法，并且在kafkaConsumer.unsubscribe（）行中，kafkaConsumer为null。但是我嘲笑了使用者，为什么它会引发空指针异常，而我应该跳过该方法，对吗？

编辑：该类的所有声明：

@Autowired
  private Consumer<String, String> kafkaConsumer;

  @Autowired
  private Service2 service2;

  private final Object lock = new Object();

  private static Logger logger = LoggerFactory.getLogger(Service.class);

  private HashMap<String, String> subscribedTopics = new HashMap<>();

找出问题所在，我需要自动连接服务

鲍勃·卢肯斯

您正在实例化一个新服务，Service service = new Service();但是据我所知，您从未将模拟bean注入到新服务中。

这是我认为如果仅使用Mockito并且不需要实例化spring容器（为了便于示例而使用单个类，请勿在实际代码中执行此操作）的情况下可以执行的操作的示例：

package com.sbp;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.runners.MockitoJUnitRunner;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@RunWith(MockitoJUnitRunner.class) // run with mockitos runner so annotations are processed
public class MyServiceTest {

    public interface Consumer<T, R> {

        public void unsubscribe();
    }

    @Service
    public class KafkaConsumer implements Consumer<String, String> {

        @Override
        public void unsubscribe() {
        }

    }

    @Service
    public class MyService {

        @Autowired
        private Consumer<String, String> kafkaConsumer;

        public void clearSubscriptions() {
            kafkaConsumer.unsubscribe();
        }
    }

    @Mock // tell mockito that this is a mock class - it will instantiate for you
    private Consumer<String, String> kafkaConsumer;

    @InjectMocks // tell mockito to inject the above mock into the class under test
    private MyService service = new MyService();

    @Test
    public void testClearSubscriptions() {
        service.clearSubscriptions();
        Mockito.verify(kafkaConsumer, Mockito.times(1)).unsubscribe();
    }
}

如果您需要使用MockBean或不使用and依赖项通过Spring获得示例，请告诉我，我可以发布。

更新：使用spring junitRunner和spring boot的mockbean注释添加示例

package com.sbp;

import com.sbp.MyServiceTest.TestContext.MyService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Service;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class) // run with spring
@SpringBootTest(classes = MyServiceTest.TestContext.class) // make it a spring boot test so @MockBean annotation is processed, provide a dummy test context class
public class MyServiceTest {

    public interface Consumer<T, R> {

        public void unsubscribe();
    }

    @Configuration
    public static class TestContext {
        @Service
        public class KafkaConsumer implements Consumer<String, String> {

            @Override
            public void unsubscribe() {
            }

        }

        @Service
        public class MyService {

            @Autowired
            private Consumer<String, String> kafkaConsumer;

            public void clearSubscriptions() {
                kafkaConsumer.unsubscribe();
            }
        }
    }

    @MockBean // this will create a mockito bean and put it in the application context in place of the Kafka consumer bean defined in the TestContext class
    private Consumer<String, String> kafkaConsumer;

    @Autowired // inject the bean from the application context that is wired with the mock bean
    private MyService myService;

    @Test
    public void testClearSubscriptions() {
        myService.clearSubscriptions();
        Mockito.verify(kafkaConsumer, Mockito.times(1)).unsubscribe();
    }
}

本文收集自互联网，转载请注明来源。

如有侵权，请联系[email protected] 删除。