分页标签

package com.spring.web.tag;

import java.io.IOException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

import org.apache.log4j.Logger;

public class PageTag extends TagSupport {

	Logger log = Logger.getLogger(PageTag.class);
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	private int total;// 总记录数
	private int currentPage = 1;// 当前页
	private int pageSize = 10;// 每页显示信息数
	private int showNum = 20;// 显示链接数
	private String css = "";
	private String style = "";
	
	private  final static String PARAM = "<input type=\"hidden\" id=\"currentPage\" name=\"currentPage\">" +
		"<script type=\"text/javascript\">function do_page(p){document.getElementById(\"currentPage\").value=p;document.forms[0].submit();}</script>";
	
	@Override
	public int doStartTag() throws JspException {

		String html = "";
		if (total > 0)
			html = html();
		else
			html = "<div style=\"text-align:right;padding-top:5px;padding-right:5px;\">未找到数据</div>";

		try {
			this.pageContext.getOut().print(html);
		} catch (IOException e) {
			log.error(e.getMessage());
			e.printStackTrace();
		}
		return super.doStartTag();
	}

	private String html() {
		
		String page = this.pageContext.getRequest().getParameter("currentPage");
		log.debug("currentPage:"+ page);
		
		if (page != null && page.length() > 0){
			this.currentPage= Integer.parseInt(page);
		}
		int totalPage = this.totalPage();
		StringBuffer result = new StringBuffer();
		if (css.trim().length() == 0 && this.style.trim().length() == 0){
			result.append("<div style=\"text-align:right;padding-top:5px;padding-right:5px;\">");
		}else{
			result.append("<div class=\"" + css + "\" style=\""+ style +"\">");
		}
		result.append("<div class=\"" + css + "\" style=\""+ style +"\">");
		result.append(PARAM);
		result.append("搜索到"+ this.total + "/" + totalPage +"条记录: &nbsp;");
		if (this.currentPage > 1){
			result.append("<a href=\"javascript:do_page(1);\">首页</a> &nbsp;");
			result.append("<a href=\"javascript:do_page(" + previousPage() + ");\">上页</a> &nbsp;");
		}
		String link = "&nbsp;<a href=\"javascript:do_page({0});\">{1}</a> &nbsp;";

		List<Integer> list = new ArrayList<Integer>();
		if (totalPage <= showNum) {
			for (int i = 1; i <= totalPage; i++) {
				list.add(i);
			}
		} else {
			Integer left = 0, right = 0;
			if(showNum % 2 == 0){
				left = showNum / 2 - 1;
				right = showNum / 2;
			}else{
				left = (showNum -1) / 2;
				right = (showNum -1) / 2;
			}
			
			if (currentPage - left < 1) {
				for (int i = 1; i <= showNum; i++) {
					list.add(i);
				}
			} else {
				if (currentPage + right >= totalPage) {
					for (int i = totalPage - showNum + 1; i <= totalPage; i++) {
						list.add(i);
					}
				} else {
					for (int i = currentPage - left; i <= currentPage + right; i++) {
						list.add(i);
					}
				}
			}
		}

		result.append("(");

		MessageFormat fmt = new MessageFormat(link);
		for (int i = 0; i < list.size(); i++) {
			if (list.get(i) == currentPage) {
				result.append("&nbsp;"+ list.get(i) +"&nbsp;");
			} else {
				Object [] p = {list.get(i), list.get(i)};
				result.append(fmt.format(p));
			}
		}
		
		result.append(")");
		if (this.currentPage < totalPage){
			result.append(" &nbsp;<a href=\"javascript:do_page(" + nextPage() + ");\">下页</a> &nbsp;");
			result.append(" <a href=\"javascript:do_page(" + totalPage + ");\">末页</a> ");
		}
		result.append("</div>");
		
		return result.toString();
	}

	private int previousPage() {
		if (this.currentPage == 1) {
			return 1;
		} else {
			return this.currentPage - 1;
		}
	}

	private int nextPage() {
		if (this.currentPage == totalPage()) {
			return totalPage();
		} else {
			return this.currentPage + 1;
		}
	}

	private int totalPage() {
                if (this.total <= this.pageSize){
                  return 1;
                }
		if (this.total % this.pageSize == 0) {
			return this.total / this.pageSize;
		} else {
			return this.total / this.pageSize + 1;
		}
	}

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public int getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}

	public String getCss() {
		return css;
	}

	public void setCss(String css) {
		this.css = css;
	}

	public int getShowNum() {
		return showNum;
	}

	public void setShowNum(int showNum) {
		this.showNum = showNum;
	}

	public String getStyle() {
		return style;
	}

	public void setStyle(String style) {
		this.style = style;
	}
}

<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
	version="2.0">
	<description>
   JSTL 2.0 core library
  </description>
	<tlib-version>1.1</tlib-version>
	<short-name>page</short-name>
	<uri>http://my.cbj.org/taglibs/page</uri>

	<tag>
		<description>分页标签</description>
		<name>page</name>
		<tag-class>com.spring.web.tag.PageTag</tag-class>
		<body-content>JSP</body-content>

		<attribute>
			<description>总记录数</description>
			<name>total</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>int</type>
		</attribute>

		<attribute>
			<description>页大小</description>
			<name>pageSize</name>
			<required>false</required>
			<rtexprvalue>true</rtexprvalue>
			<type>int</type>
		</attribute>
		
		<attribute>
			<description>样式Class</description>
			<name>css</name>
			<required>false</required>
			<rtexprvalue>false</rtexprvalue>
			<type>string</type>
		</attribute>
		
		<attribute>
			<description>样式Style</description>
			<name>style</name>
			<required>false</required>
			<rtexprvalue>false</rtexprvalue>
			<type>string</type>
		</attribute>
		
		<attribute>
			<description>显示分页链接数</description>
			<name>showNum</name>
			<required>false</required>
			<rtexprvalue>true</rtexprvalue>
			<type>int</type>
		</attribute>
	</tag>
</taglib>