还在使用@Autowrired注入？不妨试试@RequiredArgsConstructor注解完美替代

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

@RestController
@RequestMapping("/test")
@Slf4j
// 作用在类上
@RequiredArgsConstructor
public class TestController {

	// 必须声明为final类型
    private final TestService testService;
	
	// 或者使用Lombok的注解
	@NonNull
    private TestMapper testMapper;
    
    @GetMapping("/hello3")
    public int hello3(){

        Test test = new Test();
        test.setName("sss");
        test.setId("0");

        return testMapper.insert(test);
    }
}