1 先要导入一个jar包

2 自定一个标签库 ，该库放在WEB-INF/tld下面

3 需要实现 该类 extends TagSupport 实现里面的方法

4 在jsp页面引入 该标签库 并使用

5 在web.xml文件中配置该标签 （不过这个不是必须的）

6 现在给出一个显示页码的 自定义 处理类

package com.shi.utils;import java.io.IOException;
import java.util.Map;import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;import org.apache.taglibs.standard.tag.common.core.UrlSupport;/*** 显示格式 上一页 1 2 3 4 5 下一页*/
public class NavigationTag extends TagSupport {static final long serialVersionUID = 2372405317744358833L;/*** request 中用于保存Page<E> 对象的变量名,默认为“page”*/private String bean = "page";/*** 分页跳转的url地址,此属性必须*/private String url = null;/*** 显示页码数量*/private int number = 5;@Overridepublic int doStartTag() throws JspException {JspWriter writer = pageContext.getOut();HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();Page page = (Page)request.getAttribute(bean); if (page == null) return SKIP_BODY;url = resolveUrl(url, pageContext);try {//计算总页数int pageCount = page.getTotal() / page.getSize();if (page.getTotal() % page.getSize() > 0) {pageCount++;}writer.print("<nav><ul class=\"pagination\">");//显示“上一页”按钮if (page.getPage() > 1) {String preUrl = append(url, "page", page.getPage() - 1);preUrl = append(preUrl, "rows", page.getSize());writer.print("<li><a href=\"" + preUrl + "\">上一页</a></li>");} else {writer.print("<li class=\"disabled\"><a href=\"#\">上一页</a></li>");}//显示当前页码的前2页码和后两页码 //若1 则 1 2 3 4 5, 若2 则 1 2 3 4 5, 若3 则1 2 3 4 5,//若4 则 2 3 4 5 6 ,若10  则 8 9 10 11 12int indexPage = (page.getPage() - 2 > 0)? page.getPage() - 2 : 1;  for(int i=1; i <= number && indexPage <= pageCount; indexPage++, i++) {if(indexPage == page.getPage()) {writer.print( "<li class=\"active\"><a href=\"#\">"+indexPage+"<span class=\"sr-only\">(current)</span></a></li>");continue;}String pageUrl  = append(url, "page", indexPage);pageUrl = append(pageUrl, "rows", page.getSize());writer.print("<li><a href=\"" + pageUrl + "\">"+ indexPage +"</a></li>");}//显示“下一页”按钮if (page.getPage() < pageCount) {String nextUrl  = append(url, "page", page.getPage() + 1);nextUrl = append(nextUrl, "rows", page.getSize());writer.print("<li><a href=\"" + nextUrl + "\">下一页</a></li>");} else {writer.print("<li class=\"disabled\"><a href=\"#\">下一页</a></li>");}writer.print("</nav>");} catch (IOException e) {e.printStackTrace();}return SKIP_BODY;}private String append(String url, String key, int value) {return append(url, key, String.valueOf(value));}/*** 为url 参加参数对儿* * @param url* @param key* @param value* @return*/private String append(String url, String key, String value) {if (url == null || url.trim().length() == 0) {return "";}if (url.indexOf("?") == -1) {url = url + "?" + key + "=" + value;} else {if(url.endsWith("?")) {url = url + key + "=" + value;} else {url = url + "&amp;" + key + "=" + value;}}return url;}/*** 为url 添加翻页请求参数* * @param url* @param pageContext* @return* @throws javax.servlet.jsp.JspException*/private String resolveUrl(String url, javax.servlet.jsp.PageContext pageContext) throws JspException{//UrlSupport.resolveUrl(url, context, pageContext)Map params = pageContext.getRequest().getParameterMap();for (Object key:params.keySet()) {if ("page".equals(key) || "rows".equals(key)) continue;Object value = params.get(key);if (value == null) continue;if (value.getClass().isArray()) {url = append(url, key.toString(), ((String[])value)[0]);} else if (value instanceof String) {url = append(url, key.toString(), value.toString());}}return url;}/*** @return the bean*/public String getBean() {return bean;}/*** @param bean the bean to set*/public void setBean(String bean) {this.bean = bean;}/*** @return the url*/public String getUrl() {return url;}/*** @param url the url to set*/public void setUrl(String url) {this.url = url;}public void setNumber(int number) {this.number = number;}}