java：对mysql切面实现创建人创建时间更新人更新时间的赋值

背景：日常开发中，对mysql基础数据表进行设计时，几乎每个表都要有创建人创建时间更新人更新时间这四个标准字段，那么每次进行curd的时候，如果每次都要对此4个字段进行赋值，代码重复率会非常高，而且开发效率会降低，一旦漏掉操作容易导致bug。

方案：在controller方法上通过自定义注解实现aop切面。

步骤：

1、定义基类：

@Data
public class BaseEntity implements Serializable {
    private Long creatorId;
    private String creatorName;
    private Date createTime;
    private Long updaterId;
    private String updaterName;
    private Date updateTime;
}

2、定义DTO：

@Data
public class Goods extends BaseEntity {
    private String name;
}

3、自定义切面注解：

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface BaseInfoAnnotation {
    OperateTypeEnum value();
}

4、操作类型枚举：

public enum OperateTypeEnum {
    ADD,
    DELETE,
    UPDATE;
}

5、自定义 aop 操作：

public class BaseInfoAop {

    @Pointcut("@annotation(com.xx.aop.BaseInfoAnnotation))")
    public void setBaseInfo(){}

    @Around("setBaseInfo()")
    public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {
        Object res = null;
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        MetaInfoAnnotation annotation = signature.getMethod().getAnnotation(BaseInfoAnnotation.class);
        OperateTypeEnum value = annotation.value();
        Object[] args = joinPoint.getArgs();
        if (args.length > 0) {
            BaseInfo arg = (BaseInfo) args[0];
            Date now = new Date();
            UserInfo user = SessionUtil.getUser().getUserInfo();
            Long userId = user.getUserId();
            String userName = user.getRealName();
            if (value == OperateTypeEnum.ADD) {
                arg.setCreatorId(userId);
                arg.setCreatorName(userName);
                arg.setCreateTime(now);
                arg.setUpdaterId(userId);
                arg.setUpdaterName(userName);
                arg.setUpdateTime(new Date());
            } else if (value == OperateTypeEnum.UPDATE || value == OperateTypeEnum.DELETE) {
                arg.setUpdaterId(userId);
                arg.setUpdaterName(userName);
                arg.setUpdateTime(new Date());
            }

        }

        return joinPoint.proceed(args);
    }
}

6、定义Controller

@RestController
@RequestMapping("/student")
public class StudentsController {

    @BaseInfoAnnotation(value = OperateTypeEnum.ADD)
    @PostMapping("")
    public ResponseBean save(@RequestBody Students students){
        try {
            service.add(students);
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
        return new ResponseBean(true, "保存成功",  ResponseCode.SUCCESS);
    }