如何使用pagehelper分页

<c:if test="${page != null && page.getTotal() > 0 }">

<nav style="text-align: center">
		
		<ul class="pagination pagination-lg">
		
			<li><a>共 ${page.total } 条记录</a></li>
			
			<li><a>当前第 ${page.pageNum  } 页</a></li>
			
			<c:if test="${page.pageNum!= 1 }">
			
				<li><a href="?userId=${userId }&page=${page.pageNum -1}">上一页</a></li>
				
			</c:if>
			
			<c:if test="${page.pageNum < page.pages }">
			
				<li><a href="?userId=${userId }&page=${page.pageNum +1}">下一页</a></li>
				
			</c:if>
			
			<li><a>共 ${page.pages} 页</a></li>
			
		</ul>
		</nav>
	</c:if>
	
	

@RequestMapping(value = "/user/blog_list", method = RequestMethod.GET)

public ModelAndView selectAllByUserId(Integer userId,

                                      @RequestParam(required = false, defaultValue = "1") Integer page,
									  
                                      @RequestParam(required = false, defaultValue = "10") Integer rows) {
									  
    ModelAndView mv = new ModelAndView();
	//给出所要的第几页，没页多少行，默认是10页
	
    PageHelper.startPage(page, rows);
	//经过用户id得到用户全部的blog信息
    List<Blog> list = blogService.selectAllbyUserId(userId, page, rows);
	//pageInfo获取相关的页面信息
    PageInfo<Blog> p = new PageInfo<Blog>(list);
	
    mv.addObject("page", p);
	
    mv.addObject("userId", userId);
	
    mv.setViewName("user/blog_list");
	
    return mv;
}