Java 分页

分页

1.实体类设计
Page.class

import java.util.List;

/**
 * Created by Hjq on 2018/2/1.
 */
public class Page <T> {

    private int pageSize = 5;
    private int totalCount;
    private int totalpage;
    private int curenPage = 1;
    private int nextpage;
    private int prePage;
    private int firstpage;
    private int lastpage;

    private List<T> arrys; //从数据库查询出来的结果集

    public List<T> getArrys() {
        return arrys;
    }

    public void setArrys(List<T> arrys) {
        this.arrys = arrys;
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    public int getTotalCount() {
        return totalCount;
    }

    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }

    /**
     * 总共分多少页
     * @return
     */
    public int getTotalpage() {
        if(totalCount%pageSize==0)
            return totalCount/pageSize;
        else
            return totalCount/pageSize+1;
    }

    public int getCurenPage() {
        return curenPage;
    }

    public void setCurenPage(int curenPage) {
        this.curenPage = curenPage;
    }

    /**
     * 下一页
     * @return
     */
    public int getNextpage() {
        if(curenPage<this.getTotalpage())
            return curenPage+1;
        else
            return this.getTotalpage();
    }

    /***
     * 上一页
     * @param
     */
    public int getPrePage() {
        if(curenPage>1)
            return curenPage-1;
        else
            return this.getFirstpage();
    }

    /**
     * 首页
     * @return
     */
    public int getFirstpage() {
        return 1;
    }

    /**
     * 尾页
     * @return
     */
    public int getLastpage() {
        return this.getTotalpage();
    }

}

2.在对应的Service中添加分页查询

/***
     * 分页查询
     * @param page
     * @return
     */
    public Page<TRoomInfo> QueryBypage(Page<TRoomInfo> page) {
        String sql = "select count(*) from t_room_info";
        int total = dao.executeQueryCount(sql,null);
        page.setTotalCount(total);

        String sql1 = "select * from t_room_info LIMIT ?,?";
        Object[] objects = new Object[]{
                (page.getCurenPage() - 1) * page.getPageSize(),
                page.getPageSize()
        };
        List<TRoomInfo> list = dao.executeQuery(sql1,objects);
        page.setArrys(list);
        return page;
    }

3.在servlet中调用

String pageNo = request.getParameter("pageNo");
Page<TRoomInfo> page = new Page<TRoomInfo>();
if(null != pageNo)
{
page.setCurenPage(Integer.valueOf(pageNo));
}
Page<TRoomInfo> pages = service.QueryBypage(page);
request.setAttribute("page",pages);
request.getRequestDispatcher("view/Query_RoomInfo.jsp").forward(request,response);

4.页面显示

<table class="table table-striped table-hover">
   <thead>
   <tr class="success">
       <th>编号</th>
       <th>宿舍名字</th>
       <th>类型</th>
       <th>人数</th>
       <th>入住人数</th>
       <th>电话</th>
       <th>状态</th>
       <th>操作</th>
   </tr>
   </thead>
   <tbody>
   <c:forEach var="room" items="${page.arrys}">
   <tr>
       <td>${room.room_id}</td>
       <td >${room.room_no}</td>
       <td>${room.type}</td>
       <td>${room.type_num}</td>
       <td>${room.num}</td>
       <td>${room.phone}</td>
       <td>${room.status eq 'E'?"空闲":"满员"}</td>
       <td>
           <a class="btn btn-default" href="RoomServlet.do?OPER=LIST&method=queryByID&room_id=${room.room_id}">
               <span class="glyphicon glyphicon-briefcase"></span>&nbsp;修改</a>
           <a class="btn btn-default" href="RoomServlet.do?OPER=MODIFYROOM&method=del&room_id=${room.room_id}">
               <span class="glyphicon glyphicon-trash"></span>&nbsp;删除</a>
       </td>
   </tr>
   </c:forEach>
   </tbody>
   <tfoot>
   <tr>
       <td align="center" colspan="8">
           一共有${page.totalCount}条记录，共${page.totalpage}页数,当前[${page.curenPage}/${page.totalpage}]页
           <a class="btn btn-default btn-sm" href="RoomServlet.do?OPER=LIST&pageNo=${page.firstpage}">首页</a>
           <a class="btn btn-default btn-sm" href="RoomServlet.do?OPER=LIST&pageNo=${page.prePage}">上一页</a>
           <c:forEach var="index" begin="1" end="${page.totalpage}" step="1">
               <a class="btn btn-default btn-sm" href="RoomServlet.do?OPER=LIST&pageNo=${index}">${index}</a>
           </c:forEach>
           <a class="btn btn-default btn-sm" href="RoomServlet.do?OPER=LIST&pageNo=${page.nextpage}">下一页</a>
           <a class="btn btn-default btn-sm" href="RoomServlet.do?OPER=LIST&pageNo=${page.lastpage}">尾页</a>
       </td>
   </tr>
   </tfoot>
</table>

5.效果图