spring - 每次我尝试运行我的 Junit 测试用例时都出现 NullPointer 异常

Question

每次我尝试运行 junit 测试用例时，我都会得到空指针异常，并且每次函数返回 NULL 值时我都试图处理异常。这是代码。

RestaurantRepository.java

package org.springsource.restbucks;

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;


@Component
@Transactional
public interface RestaurantRepository extends PagingAndSortingRepository<Restaurant, Long> {
    @Query("SELECT p FROM Restaurant p Where (p.id)=(:Id) and p.deleted=false")
    Restaurant findById(@Param("Id") long Id);

    @Query("SELECT p FROM Restaurant p Where LOWER(p.name)=LOWER(:name) and p.deleted = false")
    Restaurant findByName(@Param("name") String name);
}

RestaurantController.java

@RestController
public class RestaurantController {
@Autowired
    RestaurantRepository repository;
@RequestMapping(value = "/restaurants/{id}", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public ResponseEntity<Restaurant> getRestaurant(@PathVariable("id") long restaurantId) {
        Restaurant responseRestaurant = repository.findOne(restaurantId);
        if(responseRestaurant==null){
            logger.error("No Restaurant found with id:"+restaurantId);
            return new ResponseEntity<Restaurant>(HttpStatus.NOT_FOUND);
        }else if(responseRestaurant.isDeleted()==true){
            logger.error("Restaurant Object is deleted");
            return new ResponseEntity<Restaurant>(HttpStatus.NOT_FOUND);
        }else{
            return new ResponseEntity<Restaurant>(responseRestaurant,HttpStatus.OK);
        }
    }

}

RestaurantRepositoryTest.java

import static org.junit.Assert.assertEquals;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

public class RestaurantRepositoryTest{

    @Autowired
    private RestaurantRepository repository;    

    @Test
    public void testfindById() throws Exception{ //testing findbyid method in restaurant repository

        Restaurant responseRestaurant = repository.findByName("xyz");   //getting error over here   
        assertEquals("xyz",responseRestaurant.getName());           
    }   
}

每当我运行 时，我都会收到空指针异常mvn 测试 .堆栈跟踪低于我在终端中显示的内容。

testfindById(org.springsource.restbucks.RestaurantRepositoryTest)
已用时间:0.018 秒 <<< 错误! java.lang.NullPointerException:
空在

org.springsource.restbucks.RestaurantRepositoryTest.testfindById(RestaurantRepositoryTest.java:19)

我该怎么做才能成功运行我的测试？

Answer 1

您将它作为没有 Spring 上下文的纯单元测试运行。因此，存储库不会 Autowiring 。您应该能够通过在测试类的顶部添加一些注释来解决这个问题。

如果使用 Spring Boot，那么类似以下内容应该可以工作，让 Spring Boot 完成所有艰苦的工作:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MyApplication.class)

您也可以加载 Spring @Configuration将初始化您的存储库的类(在我的情况下，这称为 DbConfig )，如下所示:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { DbConfig.class }, 
                      loader = AnnotationConfigContextLoader.class)