1.添加插件的依赖

<dependency>
   <groupId>com.github.pagehelper</groupId>
   <artifactId>pagehelper</artifactId>
   <version>5.0.4</version>
</dependency>

<dependency>
   <groupId>com.github.pagehelper</groupId>
   <artifactId>pagehelper-spring-boot-autoconfigure</artifactId>
   <version>1.2.5</version>
</dependency>
<dependency>
   <groupId>com.github.pagehelper</groupId>
   <artifactId>pagehelper-spring-boot-starter</artifactId>
   <version>1.2.5</version>
</dependency>
2.添加配置文件

pagehelper.helper-dialect=mysql
pagehelper.params=count=countSql
pagehelper.reasonable=true
pagehelper.support-methods-arguments=true

3.新建测试类测试

@GetMapping("/list")
@ResponseBody
public PageInfo<User>getUserList(){
//分页起始也页数和条数

 PageHelper.startPage(0,5);
//调用查询方法，此时的查询方法已经是分页返回的数据

 List<User> list=userService.selectAll();
//封装分页参数返回给前台

PageInfo pageInfo = new PageInfo(list);

return pageInfo;

}


如果失效，可以在pom里面添加aop依赖在试

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-aop</artifactId>
</dependency>