Springboot整合mybatis-plus使用pageHelper进行分页(使用步骤)

<!--pagehelper分页插件-->
<dependency>
  <groupId>com.github.pagehelper</groupId>
     <artifactId>pagehelper-spring-boot-starter</artifactId>
     <version>1.4.0</version>
</dependency>

implementation 'com.github.pagehelper:pagehelper-spring-boot-starter:1.4.0'

pagehelper:
  helper-dialect: mysql # 指定数据库方言，这里以MySQL为例
  reasonable: true # 分页合理化，如果pageNum<1会查询第一页，如果pageNum>pages会查询最后一页
  support-methods-arguments: true # 支持通过Mapper接口参数传递分页参数
  params: count=countSql # 用于从对象中根据属性名取值，这里配置count的SQL

import com.example.entity.User;
import java.util.List;
public interface UserMapper {
    @Select("SELECT * FROM user")
    List<User> selectAllUsers();
}

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.example.mapper.UserMapper;
import com.example.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    public PageInfo<User> getUserList(int pageNum, int pageSize) {
        // 设置分页参数，pageNum为当前页码，pageSize为每页显示的记录数
        PageHelper.startPage(pageNum, pageSize);
        // 执行查询
        List<User> userList = userMapper.selectAllUsers();
        // 使用PageInfo对查询结果进行包装，返回包含分页信息的对象
        return new PageInfo<>(userList);
    }
}

import com.example.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import java.util.List;
@Mapper
public interface UserMapper {
    @Select("SELECT * FROM user WHERE user_name LIKE #{name}")
    List<User> selectUsersByName(@Param("name") String name);
}

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.example.mapper.UserMapper;
import com.example.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    public PageInfo<User> getUserListByName(String name, int pageNum, int pageSize) {
        // 设置分页参数
        PageHelper.startPage(pageNum, pageSize);
        // 执行带条件的查询
        List<User> userList = userMapper.selectUsersByName("%" + name + "%");
        // 返回分页信息对象
        return new PageInfo<>(userList);
    }
}