【踩坑日志】SpringBoot项目启动提示This primary key of "id" is primitive !不建议如此请使用包装类 in Class:

![](https://blog.fivk.cn/usr/uploads/2022/06/1287903818.png)

```apache
  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.7.0)

2022-06-14 15:28:58.428  INFO 18308 --- [           main] cn.fivk.TravelApplication                : Starting TravelApplication using Java 1.8.0_321 on DESKTOP-FSSSN33 with PID 18308 (E:\ideaProject\project\Travel\target\classes started by Fivk in E:\ideaProject\project\Travel)
2022-06-14 15:28:58.430  INFO 18308 --- [           main] cn.fivk.TravelApplication                : No active profile set, falling back to 1 default profile: "default"
2022-06-14 15:28:59.152  INFO 18308 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 80 (http)
2022-06-14 15:28:59.158  INFO 18308 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-06-14 15:28:59.158  INFO 18308 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.63]
2022-06-14 15:28:59.271  INFO 18308 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-06-14 15:28:59.271  INFO 18308 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 809 ms
Logging initialized using 'class org.apache.ibatis.logging.stdout.StdOutImpl' adapter.
2022-06-14 15:28:59.360  INFO 18308 --- [           main] c.a.d.s.b.a.DruidDataSourceAutoConfigure : Init DruidDataSource
2022-06-14 15:28:59.424  INFO 18308 --- [           main] com.alibaba.druid.pool.DruidDataSource   : {dataSource-1} inited
Property 'mapperLocations' was not specified.
 _ _   |_  _ _|_. ___ _ |    _ 
| | |\/|_)(_| | |_\  |_)||_|_\ 
     /               |   
                        3.4.2 
This primary key of "id" is primitive !不建议如此请使用包装类 in Class: "cn.fivk.entity.User"
2022-06-14 15:28:59.947  INFO 18308 --- [           main] o.s.b.a.w.s.WelcomePageHandlerMapping    : Adding welcome page: class path resource [static/index.html]
2022-06-14 15:29:00.083  INFO 18308 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 80 (http) with context path ''
2022-06-14 15:29:00.090  INFO 18308 --- [           main] cn.fivk.TravelApplication                : Started TravelApplication in 1.953 seconds (JVM running for 2.51)
2022-06-14 15:29:00.092  INFO 18308 --- [           main] cn.fivk.TravelApplication                : 项目启动成功
```

## 问题原因

id 的封装应该使用Integer
</div>

如果用`int`的话`id`的默认值会是`0`，会出现一些问题，比如在`mypatisplus`使用`save`时就不能使用算法生成`id`了，这样会生成`id`为`0`的数据，如果有唯一或者主键约束的话，下一次生成就会报错。

最后修改：2022 年 06 月 14 日