分页查询(在三层框架中)

  1. 列表内容

将与分页有关的数据封装在一个对象中便于后面使用

//page<E>使用了泛型
public class Page<E> {

    private int currentPage;//当前页码
    private int pageSize;//一页几条数据
    private int totalCount;//总共有几条数据
    private int pageCount;//分了几页
    private List<E> list;//存放每页的数据
    //此处省略了set、get方法

service中需要些的方法():

    //TermPO为每一页中显示的数据的数据类型
    Page<TermPO> getTermByPage(int pageNO);

service的实现类中serviceImpl中需要些的方法:

@Override
    public Page<TermPO> getTermByPage(int pageNO) {
        // TODO Auto-generated method stub
        Page<TermPO> pageInfo = new Page<>();
        pageInfo.setCurrentPage(pageNO);
        pageInfo.setPageSize(3);
        int skip=(pageNO-1)*pageInfo.getPageSize();
        List<TermPO> list = termMapper.getTermByPage(skip, pageInfo.getPageSize());
        pageInfo.setList(list);
        pageInfo.setTotalCount(termMapper.getTermCount());

        return pageInfo;
    }

TermMapper(Term是每页显示数据的数据类型)的接口文件中写的方法

    //从索引为skip查询size条数据
    List<TermPO> getTermByPage(@Param("skip")int skip,@Param("size")int size);

TermMapper(Term是每页显示数据的数据类型)的配置文件中写对应的sql语句

<select id="getTermByPage" resultType="TermPO">
select * from user u
right join term t on u.id=t.u_id
left join term2 t2 on t2.u_id=u.id
left  join term3 t3 on t3.u_id=u.id 
group by t.id
limit #{skip},#{size}
</select>

最后在对应的controller类中调用service中分页的方法即可

public class TermController {
    
    

    @Autowired
    TermService termService;
    /*
     * @Autowired TermTtl termTtl;
     */

    // @RequestMapping("list?pageNO=${page.currentPage }")
    @RequestMapping("list")
    public ModelAndView list(Integer pageNO) {
        ModelAndView mView = new ModelAndView();
        if (pageNO == null) {
            pageNO = 1;
        }
        Page pageInfo = termService.getTermByPage(pageNO);
        mView.addObject("page", pageInfo);

        mView.setViewName("term/gyzc-list");
        return mView;
    }

注意:在jsp的跳转路径中以?的形式拼接上页码的参数即可,如下

<a  href="term/list?pageNO=${page.currentPage }">1</a> 

上下页按钮

            <c:choose>
                <c:when test="${page.currentPage <=1 }">
                    <a href="javascript:void(0)">上一页</a>
                </c:when>
                <c:otherwise>
                    <a href="term/list?pageNO=${page.currentPage-1 }">上一页</a>
                </c:otherwise>
            </c:choose>

            <c:choose>
                <c:when test="${page.currentPage >= page.pageCount }">
                    <a href="javascript:void(0)">下一页</a>
                </c:when>
                <c:otherwise>
                    <a class="product-ym_xyy" href="term/list?pageNO=${page.currentPage+1 }">下一页&gt;</a>
                </c:otherwise>
            </c:choose>

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转载自blog.csdn.net/qq_43039260/article/details/82695512