一个非常强大的SSH分页方法

分页基本上是每个项目都会用到的模块。在这里我总结了一下网上主流的分页模式，自己做了一套。跟大家分享下

这个分页方法可以完成对任意表，任意查询条件的查询和分页。基本上可以代替项目中所有的数据库查询功能，当然只限于简单逻辑上的。初步整理，有什么不妥的地方还望大家指出、探讨。

首先是分页实体类：

package engine.entity; import java.util.List; public class Pager { /** * 是否有上一页 */ private boolean hasPrePage; /** * 是否有下一页 */ private boolean hasNextPage; /** * 每页的数量 */ private int everyPage; /** * 总页数 */ private int totalPage; /** * 当前页 */ private int currentPage; /** * 起始点 */ private int beginIndex; /** * 总记录数 */ private int totalCount; /** * 该页名称 */ private String pageName; /** * 查询条件 */ private String conString; public String getConString() { return conString; } /** * 设置查询条件 */ public void setConString(String conditionString) { this.conString = conditionString; } /** * 设置该页名称（即查询表名） */ public String getPageName() { return pageName; } public void setPageName(String tableName) { this.pageName = tableName; } public int getTotalCount() { return totalCount; } /** * 设置总记录数 */ public void setTotalCount(int totalCount) { this.totalCount = totalCount; } // construct the page by everyPage public Pager(int everyPage){ this.everyPage = everyPage; } //The whole constructor public Pager(boolean hasPrePage, boolean hasNextPage, int everyPage, int totalPage, int currentPage, int beginIndex,int totalCount, String pageName,String conString) { this.hasPrePage = hasPrePage; this.hasNextPage = hasNextPage; this.everyPage = everyPage; this.totalPage = totalPage; this.currentPage = currentPage; this.beginIndex = beginIndex; this.totalCount = totalCount; this.pageName = pageName; this.conString = conString; } public int getBeginIndex() { return beginIndex; } /** * 设置起始点 */ public void setBeginIndex(int beginIndex) { this.beginIndex = beginIndex; } public int getCurrentPage() { return currentPage; } /** * 设置当前页 */ public void setCurrentPage(int currentPage) { this.currentPage = currentPage; } public int getEveryPage() { return everyPage; } /** * 设置每页的数量 */ public void setEveryPage(int everyPage) { this.everyPage = everyPage; } /** * 是否有下一页 */ public boolean getHasNextPage() { return hasNextPage; } public void setHasNextPage(boolean hasNextPage) { this.hasNextPage = hasNextPage; } /** * 是否有上一页 */ public boolean getHasPrePage() { return hasPrePage; } public void setHasPrePage(boolean hasPrePage) { this.hasPrePage = hasPrePage; } public int getTotalPage() { return totalPage; } /** * 设置总页数 */ public void setTotalPage(int totalPage) { this.totalPage = totalPage; } }

然后创建分页结果集（将分页结果打包，便于访问）：

package engine.entity; import java.util.List; public class Result { private Pager pager; private List content; //The default constructor public Result() { super(); } /** * @param 分页信息 * @param 每页显示的集合 */ public Result(Pager pager, List content) { this.pager = pager; this.content = content; } public List getContent() { return content; } public Pager getPager() { return pager; } public void setContent(List content) { this.content = content; } public void setPager(Pager pager) { this.pager = pager; } }

构建一个page的工厂PageUtil（处理分页相关计算）：

package engine; import engine.entity.Pager; public class PagerUtil { // Use the origin page to create a new page public static Pager createPage(Pager page, int totalRecords) { return createPage(page.getEveryPage(), page.getCurrentPage(),page.getPageName(), page.getConString(),totalRecords); } //the basic page utils not including exception handler public static Pager createPage(int everyPage, int currentPage, String pageName,String conString,int totalRecords) { everyPage = getEveryPage(everyPage); currentPage = getCurrentPage(currentPage); int beginIndex = getBeginIndex(everyPage, currentPage); int totalPage = getTotalPage(everyPage, totalRecords); boolean hasNextPage = hasNextPage(currentPage, totalPage); boolean hasPrePage = hasPrePage(currentPage); System.out.println(everyPage+"*"+totalPage+"*"+ currentPage+"*"+beginIndex+"*"+totalRecords); return new Pager(hasPrePage, hasNextPage, everyPage, totalPage, currentPage, beginIndex, totalRecords, pageName, conString); } private static int getEveryPage(int everyPage) { return everyPage == 0 ? 10 : everyPage; } private static int getCurrentPage(int currentPage) { return currentPage == 0 ? 1 : currentPage; } private static int getBeginIndex(int everyPage, int currentPage) { return (currentPage - 1) * everyPage; } private static int getTotalPage(int everyPage, int totalRecords) { int totalPage = 0; if (totalRecords % everyPage == 0) totalPage = totalRecords / everyPage; else totalPage = totalRecords / everyPage + 1; return totalPage; } private static boolean hasPrePage(int currentPage) { return currentPage == 1 ? false : true; } private static boolean hasNextPage(int currentPage, int totalPage) { return currentPage == totalPage || totalPage == 0 ? false : true; } }

数据访问层接口：

package hibernate.dao; import java.util.List; import engine.entity.Pager; public interface PagerProductDAO { public void setPager(Pager pager); /** * @return 分页后的数据 */ public List getProductByPage(); /** * 不使用分页 * @return 所有符合条件的数据 */ public List getProducts(); /** * @return 数据的总数 */ public int getProductCount(); }

数据访问层接口实现：

package hibernate.dao; import java.sql.SQLException; import java.util.List; import org.hibernate.HibernateException; import org.hibernate.Query; import org.hibernate.Session; import org.springframework.orm.hibernate3.HibernateCallback; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; import engine.entity.Pager; public class PagerProductDAOImpl extends HibernateDaoSupport implements PagerProductDAO { Pager pager; public Pager getPager() { return pager; } public void setPager(Pager page) { this.pager = page; } public List getProductByPage() { // TODO Auto-generated method stub return getHibernateTemplate().executeFind(new HibernateCallback(){ public Object doInHibernate(Session session) throws HibernateException, SQLException { Query query=session.createQuery("from "+pager.getPageName()+" where "+pager.getConString()); query.setFirstResult(pager.getBeginIndex()); //hibernate分页的精髓 query.setMaxResults(pager.getEveryPage()); return query.list(); } }); } public List getProducts(){ return getHibernateTemplate().find("from "+pager.getPageName()+" where "+pager.getConString()); } public int getProductCount() { // TODO Auto-generated method stub List list=getHibernateTemplate().find("from "+pager.getPageName()+" where "+pager.getConString()); return ((Integer)list.size()).intValue(); } }

业务层接口：

package engine; import engine.entity.Pager; import engine.entity.Result; public interface PagerProduct { public Result listProduct(Pager pager); }

业务层接口实现：

package engine.impl; import java.util.List; import engine.PagerProduct; import engine.PagerUtil; import engine.entity.Pager; import engine.entity.Result; import hibernate.dao.PagerProductDAO; public class PagerProductImpl implements PagerProduct { private PagerProductDAO pagerProductDAO; public PagerProductDAO getPagerProductDAO() { return pagerProductDAO; } public void setPagerProductDAO(PagerProductDAO pagerProductDAO) { this.pagerProductDAO = pagerProductDAO; } public Result listProduct(Pager pager) { // TODO Auto-generated method stub this.pagerProductDAO.setPager(pager); List products=null; if(pager.getEveryPage()==0){ //不使用分页 products = this.pagerProductDAO.getProducts(); } else{ int totalRecords = this.pagerProductDAO.getProductCount(); pager = PagerUtil.createPage(pager, totalRecords); //载入新生产的page this.pagerProductDAO.setPager(pager); products = this.pagerProductDAO.getProductByPage(); } return new Result(pager, products); } }

呼~~终于到productAction啦

public class PlaceAction extends DispatchAction { private PagerProduct pagerProduct; public PagerProduct getPagerProduct() { return pagerProduct; } public void setPagerProduct(PagerProduct pagerProduct) { this.pagerProduct = pagerProduct; } public ActionForward find(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { Pager pager=new Pager(10);//设置每页10条记录。若不想使用分页设为0即可 String tableName="Place";//查询Place表 pager.setPageName(tableName); String conditionString="Place_id>0";//设置查询条件即sql中where后面的语句 pager.setConString(conditionString); int pageNum=1;//当前显示第1页 pager.setCurrentPage(pageNum); Result result = pagerProduct.listProduct(pager); //获取新的page，此时的page已经包所有的信息 pager = result.getPager(); request.setAttribute("PlaceView", result); return mapping.findForward("PlaceView"); } }

在jsp页面中

<%@ page language="java" pageEncoding="gb2312"%> <%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %> <%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %> <bean:define id="list" name="PlaceView" property="content" type="java.util.List"></bean:define> <bean:define id="pager" name="PlaceView" property="pager" type="engine.entity.Pager"></bean:define> <bean:define id="hasNextPage" name="pager" property="hasNextPage" type="java.lang.Boolean"></bean:define> <bean:define id="hasPrePage" name="pager" property="hasPrePage" type="java.lang.Boolean"></bean:define> <logic:empty name="list"> <div id="empty"> <table border="0"> <tr> <td colspan="6">没有可以显示的数据</td> </tr> </table> </div> </logic:empty> <logic:notEmpty name="list"> <logic:iterate id="i" name="list" > <div id="place_${i.placeId }"> <table border="0"> <tr> <td> <input type="checkbox" name="selectFlag" value="${i.placeId }"> </td> <td>${i.placeId }</td> <td>${i.placeName }</td> <td>${i.placeNotes }</td> </tr> </table> </div> </logic:iterate> </logic:notEmpty> <logic:equal value="false" name="hasPrePage"> <span>[上一页]</span> </logic:equal> <logic:equal value="true" name="hasPrePage" > <span><a href="javascript:changePage(${pager.currentPage-1 })" mce_href="javascript:changePage(${pager.currentPage-1 })">[上一页]</a></span> </logic:equal> ${pager.currentPage }/${pager.totalPage } <logic:equal value="false" name="hasNextPage"> <span>[下一页]</span> </logic:equal> <logic:equal value="true" name="hasNextPage" > <span><a href="javascript:changePage(${pager.currentPage+1 })" mce_href="javascript:changePage(${pager.currentPage+1 })">[下一页]</a></span> </logic:equal>

这样所有的分页功能就完成了，至于changePage（）这个JavaScript函数就是处理翻页的动作啦，大家应该都知道了吧，就不多说了。

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