package cn.itcast.cstm.domain;import java.util.List;public class PageBean<T> {private int pc;// 當前頁碼page code//private int tp;// 總頁數total pageprivate int tr;// 總記錄數total recordprivate int ps;// 每頁記錄數page sizeprivate List<T> beanList;// 當前頁的記錄private String url;//它就是url后的條件！public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}public int getPc() {return pc;}public void setPc(int pc) {this.pc = pc;}/*** 計算總頁數* @return*/public int getTp() {// 通過總記錄數和每頁記錄數來計算總頁數int tp = tr / ps;return tr%ps==0 ? tp : tp+1;}// public void setTp(int tp) {// this.tp = tp;// }public int getTr() {return tr;}public void setTr(int tr) {this.tr = tr;}public int getPs() {return ps;}public void setPs(int ps) {this.ps = ps;}public List<T> getBeanList() {return beanList;}public void setBeanList(List<T> beanList) {this.beanList = beanList;}}

第${pb.pc }頁/共${pb.tp }頁<a href="${pb.url }&pc=1">首頁</a><c:if test="${pb.pc > 1 }"><a href="${pb.url }&pc=${pb.pc-1}">上一頁</a></c:if><%-- 計算begin、end --%><c:choose><%-- 如果總頁數不足10頁，那么把所有的頁數都顯示出來！ --%><c:when test="${pb.tp <= 10 }"><c:set var="begin" value="1" /><c:set var="end" value="${pb.tp }" /></c:when><c:otherwise><%-- 當總頁數>10時，通過公式計算出begin和end --%><c:set var="begin" value="${pb.pc-5 }" /><c:set var="end" value="${pb.pc+4 }" /> <%-- 頭溢出 --%><c:if test="${begin < 1 }"><c:set var="begin" value="1" /><c:set var="end" value="10" /></c:if> <%-- 尾溢出 --%><c:if test="${end > pb.tp }"><c:set var="begin" value="${pb.tp - 9 }" /><c:set var="end" value="${pb.tp }" /></c:if> </c:otherwise></c:choose><%-- 循環遍歷頁碼列表 --%><c:forEach var="i" begin="${begin }" end="${end }"><c:choose><c:when test="${i eq pb.pc }">[${i }]</c:when><c:otherwise><a href="${pb.url }&pc=${i}">[${i }]</a> </c:otherwise></c:choose></c:forEach><c:if test="${pb.pc < pb.tp }"><a href="${pb.url }&pc=${pb.pc+1}">下一頁</a></c:if><a href="${pb.url }&pc=${pb.tp}">尾頁</a>

package cn.itcast.cstm.web.servlet;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.itcast.commons.CommonUtils;import cn.itcast.cstm.domain.Customer;import cn.itcast.cstm.domain.PageBean;import cn.itcast.cstm.service.CustomerService;import cn.itcast.servlet.BaseServlet;public class CustomerServlet extends BaseServlet {private CustomerService customerService = new CustomerService();/*** 獲取pc* * @param request* @return*/private int getPc(HttpServletRequest request) {/** 1. 得到pc 如果pc參數不存在，說明pc=1 如果pc參數存在，需要轉換成int類型即可*/String value = request.getParameter("pc");if (value == null || value.trim().isEmpty()) {return 1;}return Integer.parseInt(value);}//分頁servletpublic String query(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// System.out.println(getUrl(request));/** 0. 把條件封裝到Customer對象中 1. 得到pc 2. 給定ps 3.* 使用pc和ps，以及條件對象，調用service方法得到PageBean 4. 把PageBean保存到request域中 5.* 轉發到list.jsp*/// 獲取查詢條件Customer criteria = CommonUtils.toBean(request.getParameterMap(), Customer.class);/** 處理GET請求方式編碼問題！*/criteria = encoding(criteria);int pc = getPc(request);// 得到pcint ps = 10;// 給定ps的值，第頁10行記錄PageBean<Customer> pb = customerService.query(criteria, pc, ps);// 得到url，保存到pb中pb.setUrl(getUrl(request));request.setAttribute("pb", pb);return "f:/list.jsp";}/*** 處理四樣* * @param criteria* @return* @throws UnsupportedEncodingException*/private Customer encoding(Customer criteria) throws UnsupportedEncodingException {String cname = criteria.getCname();String gender = criteria.getGender();String cellphone = criteria.getCellphone();String email = criteria.getEmail();if (cname != null && !cname.trim().isEmpty()) {cname = new String(cname.getBytes("ISO-8859-1"), "utf-8");criteria.setCname(cname);}if (gender != null && !gender.trim().isEmpty()) {gender = new String(gender.getBytes("ISO-8859-1"), "utf-8");criteria.setGender(gender);}if (cellphone != null && !cellphone.trim().isEmpty()) {cellphone = new String(cellphone.getBytes("ISO-8859-1"), "utf-8");criteria.setCellphone(cellphone);}if (email != null && !email.trim().isEmpty()) {email = new String(email.getBytes("ISO-8859-1"), "utf-8");criteria.setEmail(email);}return criteria;}/*** 截取url /項目名/Servlet路徑?參數字符串* * @param request* @return*/private String getUrl(HttpServletRequest request) {String contextPath = request.getContextPath();// 獲取項目名String servletPath = request.getServletPath();// 獲取servletPath，即/CustomerServletString queryString = request.getQueryString();// 獲取問號之后的參數部份// 判斷參數部份中是否包含pc這個參數，如果包含，需要截取下去，不要這一部份。if (queryString.contains("&pc=")) {int index = queryString.lastIndexOf("&pc=");queryString = queryString.substring(0, index);}return contextPath + servletPath + "?" + queryString;}}