代码：实现MetaObjectHandler类即可

@Component
public class AutoDateTimeHandler implements MetaObjectHandler {


    @Override
    public void insertFill(MetaObject metaObject) {
        this.setFieldValByName("gmtCreate", new Date(), metaObject);
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }


    @Override
    public void updateFill(MetaObject metaObject) {
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }
}

DO文件中加上注解：

    @TableField(fill = FieldFill.INSERT)
    private Date gmtCreate;

    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Date gmtModified;