实现文章上一篇下一篇

文章上下翻页显示标题

@GetMapping(value = "newsDetail")
public String newsDetail(Model model, @RequestParam(value = "nId") String nId)
{
    News n = newsService.findOne(Long.valueOf(nId.trim()));
    if (n != null) {
        List<News> newsList = newsService.findByNewsType(n.getNewsType());
        //判断元素是否存在 contains()
        if(newsList.size()!=0){
            Integer index = newsList.indexOf(n);
            n.setNextIndex(index);
            Integer upperIndex = index==0?newsList.size()-1:index-1;
            Integer lowerIndex = index==newsList.size()-1?0:index+1;
            //当前新闻为第一个时，上一篇为最后一篇
            News upperNews = newsList.get(upperIndex);
            upperNews.setNextIndex(upperIndex);
            //当前新闻为最后一个时，下一篇为第一篇
            News lowerNews = newsList.get(lowerIndex);
            lowerNews.setNextIndex(lowerIndex);
            model.addAttribute("upperNews",upperNews);
            model.addAttribute("lowerNews",lowerNews);
            model.addAttribute("news", n);
            return this.render("newsDetail");
        }
    }
    return this.render("index");
}

 前端：

                <div>
                    <span style="float: left"><a href="#"><<</a>上一篇: <a href="/az/newsDetail?nId=${upperNews.newsId?c}">${upperNews.newsTitle}</a></span>
                    <span style="float: right"><a href="#">>></a>下一篇: <a href="/az/newsDetail?nId=${upperNews.newsId?c}">${lowerNews.newsTitle}</a></span>
                </div>