java web（SSM框架）实现博客的上一篇、下一篇功能

public Blog getAfterBlog(Integer blogId) {
BlogExample blogExample = new BlogExample();
BlogExample.Criteria criteria = blogExample.createCriteria();
criteria.andBlogIdGreaterThan(blogId);
Blog blog = new Blog();
if(blogMapper.selectByExample(blogExample).size() > 0 ){
blog = blogMapper.selectByExample(blogExample).get(0);
}else{
blog.setTitle("这是最后一篇文章");
blog.setBlogId(blogId);
}
return blog;
}

@Override
public Blog getPreBlog(Integer blogId) {
BlogExample blogExample = new BlogExample();
BlogExample.Criteria criteria = blogExample.createCriteria();
criteria.andBlogIdLessThan(blogId);
Blog blog = new Blog();
if(blogMapper.selectByExample(blogExample).size() > 0 ){
blog = blogMapper.selectByExample(blogExample).get(0);
}else{
blog.setTitle("这是第一篇文章");
blog.setBlogId(blogId);
}
return blog;
}

@RequestMapping(value="/view")
public ModelAndView viewBlog(@RequestParam("blogId") Integer blogId){
//        log.debug("In viewBlog, blogID={}", blogId);
Blog blog = blogServiceImpl.getBlogById(blogId);
Blog blogPre = blogServiceImpl.getPreBlog(blogId);
Blog blogAfter = blogServiceImpl.getAfterBlog(blogId);
ModelAndView mav = new ModelAndView("blog_view");
mav.addObject("blog",blog);
mav.addObject("blogPre",blogPre);
mav.addObject("blogAfter",blogAfter);
return mav;

}

<div class="last-next">
<div>
<a href="${pageContext.request.contextPath}/blog/view?blogId=${blogPre.blogId}" title="上一篇">
<i class="icon-double-angle-left"></i>${blogPre.title}
</a>
</div>
<div>
<a href="${pageContext.request.contextPath}/blog/view?blogId=${blogAfter.blogId}" title="下一篇">
<i class="icon-double-angle-right"></i>${blogAfter.title}
</a>
</div>
</div>