java的web开发分页工具类
分页处理和储存分页用工具类。
import java.io.Serializable;import java.util.ArrayList;import java.util.List;/** * 储存分页处理工具类 在调用此类的方法之前需设置总页数(即得先从数据库查询到相应数据的数据量) * * @author ahomeeye * @version 1.0 */public class Pagination implements Serializable {private static final long serialVersionUID = 1L;private int start; // start表示当前页开始的记录数,start=每页行数*(当前页数-1)private int end; // 当前页结束的记录行数private int totalCount; // 总行数private int rowsPerPage = 15; // 每页行数，默认15private int currentPage; // 当前页数private int pageListSize = 9;// 页码列表大小，默认9private List<Integer> pageNumList = new ArrayList<Integer>();public Pagination() {start = 0;end = 0;currentPage = 1;this.totalCount = 0;}public Pagination(int totalCount) {start = 0;end = 0;currentPage = 1;this.totalCount = totalCount;}public Pagination(int totalCount, int numPerPage) {start = 0;end = 0;this.totalCount = totalCount;currentPage = 1;if (numPerPage > 0) {rowsPerPage = numPerPage;}}/** * 执行翻页动作 * * @param currentPage * 要翻到的目标页码 * @return 返回翻页对象 */public Pagination doPagination(int currentPage) {gotoPage(currentPage);return this;}// 设置起始数public int getStart() {start = rowsPerPage * (currentPage - 1);return start;}// 得到起始数public void setStart(int start) {if (start < 0) {this.start = 0;} else if (start >= this.totalCount) {this.start = this.totalCount - 1;} else {this.start = start;}}// 设置当前页的最后一行的在总记录中的顺序(从0开始)public void setEnd(int end) {this.end = end;}// 得到当前页的最后一行的在总记录中的顺序(从0开始)public int getEnd() {if (rowsPerPage * currentPage > this.totalCount) {end = this.totalCount - 1;} else {end = rowsPerPage * currentPage - 1;}return end;}// 以下4个方法供控制器(struts)调用// 判断能否到第一页;只要能到上一页，肯定就有第一页public boolean firstEnable() {return previousEnable();}// 判断能否到上一页public boolean previousEnable() {return currentPage > 1;// 只要不是第一页，就能到上一页}// 判断能否到下一页public boolean nextEnable() {return currentPage * rowsPerPage < this.totalCount;}// 判断能否到最后一页；只要有下一页，就肯定有最后一页.public boolean lastEnable() {return nextEnable();}// 跳到第一页public void firstPage() {currentPage = 1;}// 跳到上一页public void previousPage(int cPage) {currentPage = (cPage - 1) > 0 ? (cPage - 1) : 1;}// 跳到下一页public void nextPage(int cPage) {currentPage = cPage + 1;if (currentPage * rowsPerPage > this.totalCount) {lastPage();}}// 跳到最后一页public void lastPage() {if (this.totalCount % rowsPerPage == 0) {currentPage = this.totalCount / rowsPerPage;} else {currentPage = this.totalCount / rowsPerPage + 1;}}// 跳到指定的某一页public void gotoPage(int pageNumber) {if (pageNumber <= 1) {currentPage = 1;} else if (getTotalCount() < this.getRowsPerPage()) {currentPage = 1;} else if (pageNumber * rowsPerPage >= this.totalCount) {lastPage();} else {currentPage = pageNumber;}}// 设置总行数public void setTotalCount(int totalCount) {this.totalCount = totalCount;}// 得到总行数public int getTotalCount() {return totalCount;}// 设置每页行数public void setRowsPerPage(int rowsPerPage) {this.rowsPerPage = rowsPerPage;}// 得到每页行数public int getRowsPerPage() {return rowsPerPage;}// 得到总页数public int getPages() {if (this.totalCount % rowsPerPage == 0)return this.totalCount / rowsPerPage;elsereturn this.totalCount / rowsPerPage + 1;}// 得到当前页数public int getCurrentPage() {return currentPage;}// 设置当前页数public void setCurrentPage(int currentPage) {this.currentPage = currentPage;}public int getPageListSize() {return pageListSize;}// 设置页码列表大小public void setPageListSize(int pageListSize) {this.pageListSize = pageListSize;}// 得到页面列表public List<Integer> getPageNumList() {this.pageNumList.removeAll(this.pageNumList);// 设置之前先清空int totalPage = getPages();if (totalPage > this.pageListSize) {int halfSize = this.pageListSize / 2;int first = 1;int end = 1;if (this.currentPage - halfSize < 1) { // 当前页靠近最小数1first = 1;end = this.pageListSize;} else if (totalPage - this.currentPage < halfSize) { // 当前页靠近最大数first = totalPage - this.pageListSize + 1;end = totalPage;} else {first = this.currentPage - halfSize;end = this.currentPage + halfSize;}for (int i = first; i <= end; i++) {this.pageNumList.add(i);}} else {for (int i = 0; i < totalPage; i++) {this.pageNumList.add(i + 1);}}return pageNumList;}}