www.pudn.com > j2EEnews_struts_hibernate_spring.rar > PageHelper.java

package com.news.page; 
  
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpSession; 
 
 
/** 
 * 数据分页辅助类 
 * 定义每页显示记录数,并生成HTML格式的分页条 
 * @author Yinzhi Geng 
 */ 
public class PageHelper { 
	 /** 
	   * 分页条HTML代码 
	   */ 
	  public static final String BREAKPAGE =  
		  "" + 
		  "
 
  共 " + 
		  "#total} 条记录 #firstPageStart}首 页#firstPageEnd} " + 
		  "#perPageStart}上一页#perPageEnd} #nextPageStart}下一页#nextPageEnd} #lastPageStart}" + 
		  "尾 页#lastPageEnd}   页次：#page}/#allPage}  每页显示 #numPage} 条 " + 
		  "  跳转到第 #jumpPage} 页
"; 
	 
	private HttpServletRequest request; 
	private HttpSession session; 
	 
	/** 
	 * 完成初始化 
	 * 构造器 
	 * @param request 
	 */ 
	public PageHelper(HttpServletRequest request) { 
		this.request = request; 
		this.session = this.request.getSession(); 
	} 
 
	/** 
	 * 用于计算用户自定义每页显示记录数 
	 *  
	 * @return 
	 */ 
	public int doCustomPerPage(int defaultPerPage) { 
		int perPage = defaultPerPage; 
		String cUserPerPage = null; 
		String cPerPage = StringUtil.getString(request.getParameter("perPage")); 
		if (!"".equals(cPerPage)) { 
			this.session.setAttribute("cPerPage", cPerPage); 
		} 
		cUserPerPage = (String) this.session.getAttribute("cPerPage"); 
		if (null != cUserPerPage) { 
			perPage = Integer.parseInt(cUserPerPage); 
		} 
		return perPage; 
	} 
	 
	/** 
	 * 获取HTML格式分页条 
	 * @param pageObject 
	 * @return 
	 */ 
	public String getPageBreakStr(Page pageObject) { 
		int page = 1; 
		int total = 0; 
		int perPage = 20; 
		 
		/** 
		 * 取分页器参数 
		 */ 
		page = pageObject.getPage(); 
		total = pageObject.getTotal(); 
		perPage = pageObject.getPerPage(); 
 
		String contextPath = pageObject.getContextPath(); 
		String url = contextPath + pageObject.getUrl(); 
		String param = pageObject.getParam(); 
		/** 
		 * 定义显示控制 
		 * display1:首页 
		 * display2:上一页 
		 * display3:下一页 
		 * display4:最后一页 
		 */ 
		boolean display1 = false; 
		boolean display2 = false; 
		boolean display3 = false; 
		boolean display4 = false; 
		boolean isHaveParam=false; 
		 
		if(null!=param && !"".equals(param)){ 
			isHaveParam = true; 
		} 
 
		int totalPage = (total + perPage - 1) / perPage; 
		if (page > totalPage || page < 0) { 
			page = 1; 
		} 
 
		/** 
		 * 首页 
		 */ 
		StringBuffer firstPageBuffer = new StringBuffer(); 
		if (totalPage > 1) { 
			firstPageBuffer.append(url + "?page=1"); 
			if(isHaveParam){ 
				firstPageBuffer.append("&"+param); 
			} 
			display1 = true; 
		} 
 
		/** 
		 * 上一页 
		 */ 
		StringBuffer perPageBuffer = new StringBuffer(); 
		if (page > 1) { 
			perPageBuffer.append(url + "?page=" + (page - 1)); 
			if(isHaveParam){ 
				perPageBuffer.append("&"+param); 
			} 
			display2 = true; 
		} 
 
		/** 
		 * 下一页 
		 */ 
		StringBuffer nextPageBuffer = new StringBuffer(); 
		if (page < totalPage) { 
			nextPageBuffer.append(url + "?page=" + (page + 1)); 
			if(isHaveParam){ 
				nextPageBuffer.append("&"+param); 
			} 
			display3 = true; 
		} 
 
		/** 
		 *  最后一页 
		 */ 
		StringBuffer lastPageBuffer = new StringBuffer(); 
		if (totalPage > 1) { 
			lastPageBuffer.append(url + "?page=" + totalPage); 
			if(isHaveParam){ 
				lastPageBuffer.append("&"+param); 
			} 
			display4 = true; 
		} 
 
		/** 
		 * 每页显示记录数 
		 */ 
		StringBuffer numPageBuffer = new StringBuffer(); 
		numPageBuffer.append(""); 
		for (int i = 1; i <= 4; i++) { 
			numPageBuffer.append("" + (i * 10) + ""); 
			} else { 
				numPageBuffer.append(">" + (i * 10) + ""); 
			} 
		} 
		numPageBuffer.append(""); 
 
		/** 
		 * 跳转到第几页 
		 */ 
		StringBuffer jumpPageBuffer = new StringBuffer(); 
		jumpPageBuffer.append(""); 
		for (int i = 1; i <= totalPage; i++) { 
			jumpPageBuffer.append("" + i + ""); 
		} 
		jumpPageBuffer.append(""); 
		 
		/** 
		 * 整个分页条 
		 */ 
		String deTemplateString = ""; 
		try { 
			/** 
			 * 获取分页条HTML显示 
			 */ 
			deTemplateString = BREAKPAGE; 
			 
			/** 
			 * 替换HTML代码的标记 
			 */ 
			deTemplateString = deTemplateString.replaceAll("#total}", String 
					.valueOf(total)); 
			deTemplateString = deTemplateString.replaceAll("#page}", String 
					.valueOf(page)); 
			deTemplateString = deTemplateString.replaceAll("#allPage}", String 
					.valueOf(totalPage)); 
			if (display1) { 
				deTemplateString = deTemplateString.replaceAll("#firstPageStart}", 
						""); 
				deTemplateString = deTemplateString.replaceAll("#firstPageEnd}",""); 
			}else{ 
				deTemplateString = deTemplateString.replaceAll("#firstPageStart}",""); 
				deTemplateString = deTemplateString.replaceAll("#firstPageEnd}",""); 
			} 
			if (display2) { 
				deTemplateString = deTemplateString.replaceAll("#perPageStart}", 
						""); 
				deTemplateString = deTemplateString.replaceAll("#perPageEnd}",""); 
			}else{ 
				deTemplateString = deTemplateString.replaceAll("#perPageStart}",""); 
				deTemplateString = deTemplateString.replaceAll("#perPageEnd}",""); 
			} 
			if (display3) { 
				deTemplateString = deTemplateString.replaceAll("#nextPageStart}", 
						""); 
				deTemplateString = deTemplateString.replaceAll("#nextPageEnd}",""); 
			}else{ 
				deTemplateString = deTemplateString.replaceAll("#nextPageStart}",""); 
				deTemplateString = deTemplateString.replaceAll("#nextPageEnd}",""); 
			} 
			if (display4) { 
				deTemplateString = deTemplateString.replaceAll("#lastPageStart}", 
						""); 
				deTemplateString = deTemplateString.replaceAll("#lastPageEnd}",""); 
			}else{ 
				deTemplateString = deTemplateString.replaceAll("#lastPageStart}",""); 
				deTemplateString = deTemplateString.replaceAll("#lastPageEnd}",""); 
			} 
			deTemplateString = deTemplateString.replaceAll("#numPage}", 
					numPageBuffer.toString()); 
			deTemplateString = deTemplateString.replaceAll("#jumpPage}", 
					jumpPageBuffer.toString()); 
		} catch (Exception e) { 
			e.printStackTrace(); 
		} 
		System.out.println(deTemplateString); 
		return deTemplateString; 
	} 
}