关于springboot整合mybaits的mapper无法注入/空指针问题

1.依赖关系

我按照官网首页所说导入了下面的依赖，结果无法注入mapper

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus</artifactId>
    <version>3.5.1</version>
</dependency>

解决：再导入springboot相关的mybatis-plus依赖

<dependency>
 <groupId>com.baomidou</groupId>
 <artifactId>mybatis-plus-boot-starter</artifactId>
 <version>3.5.1</version>
 </dependency>

2.mapper注入的测试路径问题

最开始的测试路径我是直接写在了test目录下面，结果导致springboot无法找到测试类

Unable to find a @SpringBootConfiguration,
 you need to use @ContextConfiguration or @SpringBootTest(classes=...)
 with your test

之后加上了classes之后不报此错误，此处classes为springboot的主启动类

@SpringBootTest(classes = SpringbootMybatisplusApplication.class)