分页类实例 java

保存代码片段

 

分页类：

package cn.news.vo;

import java.util.List;
/**
 * 用于在页面上使用的数据类，包含有分页的信息及相应的数据
 * @author Administrator
 * @param <T> 检索的数据实体类型
 */
public class PageData<T> {
    private List<T> list ;
    private boolean isFirst=false;        //是否是首页
    private boolean isEnd=false;        //是否是尾页
    private int page=1;            //跳转页,默认为第一页
    private int count=10;        //每页的记录数，默认每页显示10条记录
    private int totalPage;        //总共的页码
    private int totalRows;        //总共的记录数
    private int realRowIndex;    //该分页在数据库中真实的记录行数
    
    /**
     * 在DaoImpl中取得查询实体的总记录后设置该属性
     * 跳转的页面、每页的记录、总记录，三个已知可以确定本类中的分页属性
     * @param totalRows
     */
    public void setTotalRows(int totalRows) {
        if (totalRows==0) {
            totalPage = 1 ;
        }else{
            this.totalPage = totalRows/count+1 ;        //可以得到全部的页面
        }
        this.init();                                    //设置分页的基本数据
        this.totalRows = totalRows;
    }
    
    public void init(){                                    //初始化分页的基本数据
        if(page < 1){
            page = 1 ;
        }
        if(page<totalPage){
            if(page==1){
                isFirst = true ;
                isEnd = false ;
            }
        }else if(page==totalPage){
            if (page==1) {
                isFirst = true ;
                isEnd = true ;
            }else{
                isFirst = false ;
                isEnd = true ;
            }
        }else if(page>totalPage){
            page = totalPage;
            if (totalPage==1) {
                isFirst = true ;
                isEnd = true ;
            }else {
                isFirst = false ;
                isEnd = true ;
            }    
        }
        realRowIndex = (page-1)*count ;
    }
    @Override
    public String toString() {
        return "PageData [isFirst=" + isFirst + ", isEnd=" + isEnd + ", page="
                + page + ", count=" + count + ", totalPage=" + totalPage
                + ", totalRows=" + totalRows + ", realRowIndex=" + realRowIndex
                + "]";
    }
    public List<T> getList() {
        return list;
    }
    public void setList(List<T> list) {
        this.list = list;
    }
    public int getRealRowIndex() {
        return realRowIndex;
    }
    public int getPage() {
        return page;
    }
    public void setPage(int page) {
        this.page = page;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
    }
    public int getTotalPage() {
        return totalPage;
    }
    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }
    public boolean getIsFirst() {
        return isFirst;
    }
    public void setIsFirst(boolean isFirst) {
        this.isFirst = isFirst;
    }
    public boolean getIsEnd() {
        return isEnd;
    }
    public void setIsEnd(boolean isEnd) {
        this.isEnd = isEnd;
    }
    public int getTotalRows() {
        return totalRows;
    }
}

使用 Hibernate 的 DaoImpl 中的方法：

public PageData<V> findOnPage(PageData<V> page) {
        List<V> list = null ;
        String hql = "from "+ this.entityClazz.getName()+" order by id desc";
        try {
            page.setTotalRows(getTotalRows());
            list = this.getSession().createQuery(hql)
                                    .setFirstResult(page.getRealRowIndex())
                                    .setMaxResults(page.getCount())
                                    .list();
            page.setList(list);
        } catch (DataAccessResourceFailureException e) {
            e.printStackTrace();
        } catch (HibernateException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        }
        return page;
    }

前台导航栏（Struts2 标签）：

pageData为 action 中的分页类的对象

<td>
          <s:if test="pageData.isFirst">
              &nbsp;首页&nbsp;|&nbsp;
              上一页&nbsp;|&nbsp;
          </s:if>
        <s:else>
            <a href="newsAction-findByPage?pageData.page=1">首页</a>&nbsp;|&nbsp;
            <a href="newsAction-findByPage?pageData.page=${pageData.page-1}">上一页</a>&nbsp;|&nbsp;
        </s:else>
        <s:if test="pageData.isEnd">
            下一页&nbsp;|&nbsp;
            尾页&nbsp;|&nbsp;
        </s:if>
        <s:else>
            <a href="newsAction-findByPage?pageData.page=${pageData.page+1}">下一页</a>&nbsp;|&nbsp;
            <a href="newsAction-findByPage?pageData.page=${pageData.totalPage}">尾页</a>&nbsp;|&nbsp;
        </s:else>
            转到&nbsp;<input type="text" style="width: 30px">&nbsp;页
            <input type="button" value="跳转" />,共&nbsp;${pageData.totalPage}&nbsp;页
        </td>