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。