MyBatis-Plus实现字段自动填充功能的示例

@Data
@TableName("t_user")
public class User extends BaseEntity<User> {

    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;
 
    @TableField("username")
    private String username;
    
    @Override
    protected Serializable pkVal() {
        return this.id;
    }
}

@Getter
@Setter
public abstract class BaseEntity<T extends Model> extends Model {
    
    @TableField(value = "gmt_create", fill = FieldFill.INSERT)
    private Date gmtCreate;
	
    @TableField(value = "gmt_modified", fill = FieldFill.INSERT_UPDATE)
    private Date gmtModified;
}

public enum FieldFill {
    DEFAULT(0, "默认不处理"),
    INSERT(1, "插入填充字段"),
    UPDATE(2, "更新填充字段"),
    INSERT_UPDATE(3, "插入和更新填充字段");
    
    private final int key;
    
    private final String desc;
    FieldFill(final int key, final String desc) {
        this.key = key;
        this.desc = desc;
    }
    public static FieldFill getIgnore(int key) {
        FieldFill[] fis = FieldFill.values();
        for (FieldFill fi : fis) {
            if (fi.geTKEy() == key) {
                return fi;
            }
        }
        return FieldFill.DEFAULT;
    }
    public int getKey() {
        return this.key;
    }
    public String getDesc() {
        return this.desc;
    }
}

@Component
public class MyMetaObjectHandler extends MetaObjectHandler {

    private static final Logger LOG = LoggerFactory.getLogger(MyMetaObjectHandler.class);

    
    @Override
    public void insertFill(MetaObject metaObject) {
        LOG.info(" -------------------- start insert fill ...  --------------------");
        if (metaObject.hasGetter("gmtCreate") && metaObject.hasGetter("gmtModified")) {
            setFieldValByName("gmtCreate", new Date(), metaObject);
            setFieldValByName("gmtModified", new Date(), metaObject);
        }
    }

    
    @Override
    public void updateFill(MetaObject metaObject) {
        LOG.info(" -------------------- start update fill ...  --------------------");
        if (metaObject.hasGetter("et.gmtModified")) {
            setFieldValByName("gmtModified", new Date(), metaObject);
        }
    }
    
}