基于hibernate实现的分页技术实例分析

本文实例讲述了基于hibernate实现的分页技术。分享给大家供大家参考，具体如下：

先说明一下基于hibernate实现分页的原理，假如从数据库取出100条数据，我们要让每页显示10条，假如从30开始，只需要设置起始位置和最大的返回结果即可
先上代码：注意传进来的参数有 page这类，后面有介绍

public list<article> querybypage(final string username, final page page) {
    return this.gethibernatetemplate().executefind(new hibernatecallback() {
      public object doinhibernate(session session)
          throws hibernateexception, sqlexception {
        query query = session.createquery("select art from article art where art.username = ?");
        //设置参数
        query.setparameter(0, username);
        //设置每页显示多少个，设置多大结果。
        query.setmaxresults(page.geteverypage());
        //设置起点
        query.setfirstresult(page.getbeginindex());
        return query.list();
      }
});

上面关键代码是 setmaxresults(),和setfirstresult(),即设置最大显示值和起点

这里我们需要一个page工具类，用来操作分页。

page.java：

package com.fenye;
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
  public int geteverypage() {
    return everypage;
  }
  public void seteverypage(int everypage) {
    this.everypage = everypage;
  }
  public int gettotalcount() {
    return totalcount;
  }
  public void settotalcount(int totalcount) {
    this.totalcount = totalcount;
  }
  public int gettotalpage() {
    return totalpage;
  }
  public void settotalpage(int totalpage) {
    this.totalpage = totalpage;
  }
  public int getcurrentpage() {
    return currentpage;
  }
  public void setcurrentpage(int currentpage) {
    this.currentpage = currentpage;
  }
  public int getbeginindex() {
    return beginindex;
  }
  public void setbeginindex(int beginindex) {
    this.beginindex = beginindex;
  }
  public boolean ishasprepage() {
    return hasprepage;
  }
  public void sethasprepage(boolean hasprepage) {
    this.hasprepage = hasprepage;
  }
  public boolean ishasnextpage() {
    return hasnextpage;
  }
  public void sethasnextpage(boolean hasnextpage) {
    this.hasnextpage = hasnextpage;
  }
}

page工具类主要是封装页面信息，一共多少数据啊，一页显示多少啊，起点的序号，总页数，是否有上一页下一页，当前页。

还需要一个操作page的工具类，pageutil.java

package com.sanqing.fenye;
/*
 * 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;
  }
}

创建page只需要3个参数，每页显示多少数据，当前页，总共多少数据，其他的4个参数都可以通过这三个计算出来

所以后面要创建page，只需要调用这工具方法pageutil.createpage(3个参数)，就返回一page.

返回的page就是前面参数的page，即要显示的分页

这样就算完成了分页的功能。

希望本文所述对大家基于hibernate框架的java程序设计有所帮助。