PageHelper分页插件的使用

1.引入依赖?

    <!-- pagehelper 分页插件 -->
		<dependency>
			<groupId>com.github.pagehelper</groupId>
			<artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.4.7</version>
		</dependency>

2.application.yml 配置

# PageHelper分页插件
pagehelper:
  helperDialect: mysql
  supportMethodsArguments: true
  params: count=countSql

3.PageUtil

/**
 * 分页工具类
 * @author: jzm   
 */
public class PageUtil
{

    private static <T> Page<T> _startPage(int pageNum, int pageSize, ISelect select, String orderBy)
    {
        Page<T> page = PageHelper.startPage(pageNum, pageSize).doSelectPage(select);
        if (orderBy == null)
        {
            return page;
        }
        page.setOrderBy(orderBy);
        return page;
    }

    /**
     * 分页
     *
     * @param select : () -> userMapper.list()
     */
    public static <T> PageInfo<T> startPage(int pageNum, int pageSize, ISelect select)
    {
        return new PageInfo<>(_startPage(pageNum, pageSize, select, null));
    }

    /**
     * 降序 + 分页
     */
    public static <T> PageInfo<T> orderByDesc(int pageNum, int pageSize, String filed, ISelect select)
    {
        return new PageInfo<>(_startPage(pageNum, pageSize, select, filed + " desc"));
    }


    /**
     * 升序 + 分页
     */
    public static <T> PageInfo<T> orderByAsc(int pageNum, int pageSize, String filed, ISelect select)
    {
        return new PageInfo<>(_startPage(pageNum, pageSize, select, filed + " asc"));
    }

    /**
     * 清理分页的线程变量
     */
    public static void clearPage()
    {
        PageHelper.clearPage();
    }


}

?4. 测试

   @Test
    public void mapperTest(){
        PageInfo<Object> pageInfo = PageUtil.startPage(1, 10, () ->
        {
           service.findUserList(); // 要执行的service、mappere查询操作都可以
        });
        System.out.println(12);
    }

调试看一波。嗯...?