使用pager-taglib.jar实现的分页技术

//1.导入pager-taglib.jar包； //2.引入pager-taglib标签：<%@ taglib prefix="pg" uri="http://jsptags.com/tags/navigation/pager" %> //3.建立PagerModel类： public class PagerModel { /** * 总记录数 */ private int total; /** * 当前页结果集 */ private List datas; public List getDatas() { return datas; } public void setDatas(List datas) { this.datas = datas; } public int getTotal() { return total; } public void setTotal(int total) { this.total = total; } } //4.pager业务逻辑部分： public class AbstractManager extends HibernateDaoSupport { public PagerModel searchHql(String hql){ return searchHql(hql,null,SystemContext.getOffset(),SystemContext.getPageSize()); } public PagerModel searchHql(String hql,Object datas){ return searchHql(hql,new Object[]{datas},SystemContext.getOffset(),SystemContext.getPageSize()); } public PagerModel searchHql(String hql,Object[] datas){ return searchHql(hql,datas,SystemContext.getOffset(),SystemContext.getPageSize()); } public PagerModel searchHql(String hql,int offset,int pageSize){ return searchHql(hql,null,offset,pageSize); } public PagerModel searchHql(String hql,Object datas,int offset,int pageSize){ return searchHql(hql,new Object[]{datas},offset,pageSize); } public PagerModel searchHql(String hql,Object[] datas,int offset,int pageSize){ String countHql = getQuery(hql); Query query = getSession().createQuery(countHql); if(datas !=null && datas.length > 0){ for(int i = 0 ; i<datas.length;i++) query.setParameter(i, datas[i]); } int total = ((Long)query.uniqueResult()).intValue(); Query query1=getSession().createQuery(hql); if(datas !=null && datas.length > 0){ for(int i = 0 ; i<datas.length;i++) query1.setParameter(i, datas[i]); } List list =query1.setFirstResult(offset) .setMaxResults(pageSize).list(); PagerModel pm = new PagerModel(); pm.setDatas(list); pm.setTotal(total); return pm; } public String getQuery(String hql){ int index =hql.indexOf("from"); if(index != -1){ return "select count(*)"+hql.substring(index); } throw new SystemException("查询语句出错！"); } } //5.定义offset、pagesize类： public class SystemContext { private static ThreadLocal offset = new ThreadLocal(); private static ThreadLocal pageSize = new ThreadLocal(); public static int getOffset(){ Integer os = (Integer)offset.get(); if(os == null){ return 0; } return os; } public static void setOffset(int offsetvalue){ offset.set(offsetvalue); } public static void removeOffset(){ offset.remove(); } public static int getPageSize(){ Integer ps = (Integer)pageSize.get(); if(ps == null){ return Integer.MAX_VALUE; } return ps; } public static void setPageSize(int pageSizevalue){ pageSize.set(pageSizevalue); } public static void removePageSize(){ pageSize.remove(); } } //6.过滤器中初始化pagesize、offset： public class PagerFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest httpRequest =(HttpServletRequest)request; SystemContext.setOffset(getOffset(httpRequest)); SystemContext.setPageSize(getPageSize(httpRequest)); try{ chain.doFilter(request, response); }finally{ //清空ThreadLocal中的值 SystemContext.removeOffset(); SystemContext.removePageSize(); } } public void init(FilterConfig arg0) throws ServletException { } public int getOffset(HttpServletRequest request){ int offset = 0; try { offset = Integer.parseInt(request.getParameter("pager.offset")); } catch (NumberFormatException ignore) { } return offset; } //设置每页显示多少条记录 public int getPageSize(HttpServletRequest request){ return 3; } } //7.配置过滤器web.xml中： <filter> <filter-name>pager-taglib</filter-name> <filter-class>com.oa.util.filter.PagerFilter</filter-class> </filter> <filter-mapping> <filter-name>pager-taglib</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> //8.显示效果： <pg:pager url="org.do" items="${pm.total }" export="currentPageNumber=pageNumber"> <pg:param name="parentId"/> <pg:first> <a href="${pageUrl}" mce_href="${pageUrl}">首页</a> </pg:first> <pg:prev> <a href="${pageUrl }" mce_href="${pageUrl }">前页</a> </pg:prev> <pg:pages> <c:choose> <c:when test="${currentPageNumber eq pageNumber }"> <font color="red">${pageNumber }</font> </c:when> <c:otherwise> <a href="${pageUrl }" mce_href="${pageUrl }">${pageNumber }</a> </c:otherwise> </c:choose> </pg:pages> <pg:next> <a href="${pageUrl }" mce_href="${pageUrl }">后页</a> </pg:next> <pg:last> <a href="${pageUrl }" mce_href="${pageUrl }">尾页</a> </pg:last> </pg:pager>