spring 注入方式为2种，构造器注入和setter 注入

使用Lombok 进行setter 注入(尽量优先使用setter 注入)

@Service
@Setter(onMethod_ = {@Autowired})
public class TestServiceImpl implements TestService {

   private TestDao testDao;

}

看一下编译的内容

@Service
public class TestServiceImpl implements TestService {

   private TestDao testDao;

   @Autowired
   public void setTestDao(final TestDao testDao) { 
     this.testDao = testDao;

   }

}

使用Lombok 进行构造器注入

Service
@RequireArgsConstructor(onConstructor_ ={@Autowired}) 
public class TestServiceImpl implements TestService {

   private final TestDao testDao;


}

或

@Service
@RequiredArgsConstructor(onConstructor_ = {@Autwired})
public class TestServiceImpl implements TestService {
     @lombok.NonNull 
     private TestDao testDao;

}

编译的内容

@Service
public class TestServiceImpl implements TestService {

   private TestDao testDao;
     

   @Autowired
   public void TestServiceImpl(final TestDao testDao) {
      this.testDao = testDao;
   }
}