Lombok @RequiredArgsConstructor annotation

How do you usually use spring dependency injection?

@RestController
@RequestMapping("alarm/configs")
public class AlarmConfigController {
    @Autowired
    private AlarmConfigService alarmConfigService;
...
}

Is it a familiar feeling? But if you use IDEA, it will prompt you

Probably spring does not recommend using this method. There are many reasons online: https://blog.csdn.net/github_38222176/article/details/79506392

The following is the wording recommended by spring:

@RestController
@RequestMapping("alarm/configs")
public class AlarmConfigController {
    private final AlarmConfigService alarmConfigService;

    @Autowired
    public AlarmConfigController(AlarmConfigService alarmConfigService) {
        this.alarmConfigService = alarmConfigService;
    }
...
}

If too many classes are injected, it looks very cumbersome. Recently, I accidentally found that using Lombok can write concise code on the Internet:

Later, I found that this method has a chance to cause Spring circular references, so it is still not recommended.

@RestController
@RequestMapping("alarm/configs")
@RequiredArgsConstructor
public class AlarmConfigController {
    //这里必须是final,若不使用final,用@NotNull注解也是可以的
    private final AlarmConfigService alarmConfigService;
...
}

 This way of writing is actually the same as the one recommended by spring after compilation. Isn’t it very concise?

Reference https://my.oschina.net/yejunxi/blog/2209101