使用Junit Test时，@Autowired 注入出现空指针异常NullPointerException问题

1.添加maven依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>

2.测试类添加注解

@RunWith(SpringRunner.class)
@SpringBootTest

3.完成～～