Jsp中翻页功能实现

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Jsp中翻页功能实现

第一步：新建两个辅助类

Page类

    public class Page {
      // 1.每页显示数量(everyPage)
      private int everyPage;
      // 2.总记录数(totalCount)
      private int totalCount;
      // 3.总页数(totalPage)
      private int totalPage;
      // 4.当前页(currentPage)
      private int currentPage;
      // 5.起始点(beginIndex)
      private int beginIndex;
      // 6.是否有上一页(hasPrePage)
      private boolean hasPrePage;
      // 7.是否有下一页(hasNextPage)
      private boolean hasNextPage;

   public Page(int everyPage, int totalCount, int totalPage, int currentPage,
           int beginIndex, boolean hasPrePage, boolean hasNextPage) {
       this.everyPage = everyPage;
       this.totalCount = totalCount;
       this.totalPage = totalPage;
       this.currentPage = currentPage;
       this.beginIndex = beginIndex;
       this.hasPrePage = hasPrePage;
       this.hasNextPage = hasNextPage;
   }
   //构造函数，默认
   public Page(){}

   //构造方法，对所有属性进行设置
    //*****此处省略set及get构造方法****
    }

PageUtil类

    package com.iven.help;
    /*
     * 分页信息辅助类
    */
    public class PageUtil {

   public static Page createPage(int everyPage,int totalCount,int currentPage) {
       everyPage = getEveryPage(everyPage);
       currentPage = getCurrentPage(currentPage);
       int totalPage = getTotalPage(everyPage, totalCount);
       int beginIndex = getBeginIndex(everyPage, currentPage);
       boolean hasPrePage = getHasPrePage(currentPage);
       boolean hasNextPage = getHasNextPage(totalPage, currentPage);
       return new Page(everyPage, totalCount, totalPage, currentPage,
               beginIndex, hasPrePage, hasNextPage);
   }
   public static Page createPage(Page page,int totalCount) {
       int everyPage = getEveryPage(page.getEveryPage());
       int currentPage = getCurrentPage(page.getCurrentPage());
       int totalPage = getTotalPage(everyPage, totalCount);
       int beginIndex = getBeginIndex(everyPage, currentPage);
       boolean hasPrePage = getHasPrePage(currentPage);
       boolean hasNextPage = getHasNextPage(totalPage, currentPage);
       return new Page(everyPage, totalCount, totalPage, currentPage,
               beginIndex, hasPrePage, hasNextPage);
   }
   //设置每页显示记录数
   public static int getEveryPage(int everyPage) {
       return everyPage == 0 ? 10 : everyPage;
   }
   //设置当前页
   public static int getCurrentPage(int currentPage) {
       return currentPage == 0 ? 1 : currentPage;
   }
   //设置总页数,需要总记录数，每页显示多少
   public static int getTotalPage(int everyPage,int totalCount) {
       int totalPage = 0;
       if(totalCount % everyPage == 0) {
           totalPage = totalCount / everyPage;
       } else {
           totalPage = totalCount / everyPage + 1;
       }
       return totalPage;
   }
   //设置起始点，需要每页显示多少，当前页
   public static int getBeginIndex(int everyPage,int currentPage) {
       return (currentPage - 1) * everyPage;
   }
   //设置是否有上一页，需要当前页
   public static boolean getHasPrePage(int currentPage) {
       return currentPage == 1 ? false : true;
   }
   //设置是否有下一个，需要总页数和当前页
   public static boolean getHasNextPage(int totalPage, int currentPage) {
       return currentPage == totalPage || totalPage == 0 ? false : true;
   }
    }

第二步：在Action类中创建Page对象，并存入到Session中

       public String getUserList(){

       //从Session中获取用户
       User user=(User)ActionContext.getContext().getSession().get("user");
       System.out.println(user.getId());

       //从request对象中获取currentPage的值

StringcurPage=ServletActionContext.getRequest().getParameter("currentPage").toString()

int currentPage=Integer.parseInt(curPage);

   //根据uid从Server层中获取User表中的总数
       int totalCount=userDao.getCountByUid(user.getId());
        //通过PageUtil的createPage静态方法创建page对象
       Page page=PageUtil.createPage(3, totalCount, currentPage);

//根据page及uid获取users列表

List<User> users=userDao.findUserByPage(page,user.getId());

//将users及page存入到Session中

        ActionContext.getContext().getSession().put("users",users);
       ActionContext.getContext().getSession().put("page", page);

        return SUCCESS;
   }
    第三步：在Dao层中中获取数据对象

获取表中记录总数，

public ClassuserDao{

    public int getCountByUid(int uid){
       List<User> users=null;
       Query query=getSession().createQuery("from Userwhere uid="+uid);
       users=query.list();
       return users.size();
   }
    根据page及uid获取user列表
   public List<User> findUserByPage(Page page,int uid) {
       Query query=getSession().createQuery("from User");
       query.setMaxResults(page.getEveryPage());
       query.setFirstResult(page.getCurrentPage());
       List<User> users=query.list();
       return repairs;
   }

}

第四步：在Jsp页面中使用page对象实现翻页

<tr >

<td colspan="9" align="center" >
       共${page.totalCount }条记录，当前第${page.currentPage }/${page.totalPage }页，每页${page.everyPage }条记录
          <a href="getUserList.action?currentPage=1" >首页</a>|
          <a href="getUserList.action?currentPage=${page.currentPage -1}" >上一页</a>|
          <a href="getUserList.action?currentPage=${page.currentPage +1}" >下一页</a>|
          <a href="getUserList.action?currentPage=${page.totalPage }" >尾页</a>
       </td>

</tr>

第五步：测试

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