分页封装类

加油，新时代打工人！

package com.love.starter.common.util;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import java.util.Map;/*** 计算页开始及结束位置** @author Administrator*/
public class Page {public static final int PAGE_SIZE_TWENTY = 20;public static final int PAGE_SIZE_TEN = 10;public static final int PAGE_SIZE_TWELVE = 12;/*** 默认每页数量*/private static final int DEFAULT_SIZE = 15;public static final int PAGE_SIZE_SEVEN = 7;public static final int PAGE_SIZE_FIFTY = 50;public static final int PAGE_SIZE_EIGHT = 8;public static final int PAGE_SIZE_FOURTEEN = 14;public static final int PAGE_SIZE_FIVE = 5;/*** 开始位置*/private final int start;/*** 结束位置*/private final int end;/*** 第几页*/private int pageIndex = 1;/*** 每页记录数*/private int pageSize = DEFAULT_SIZE;/*** 默认第一页，每页15行** @param request*/public Page(HttpServletRequest request) {String index = getPageIndex(request);String size = getPageSize(request);if (Nulls.isNotEmpty(index)) {pageIndex = Integer.parseInt(index);}if (Nulls.isNotEmpty(size)) {pageSize = Integer.parseInt(size);}start = (pageIndex - 1) * pageSize + 1;end = pageIndex * pageSize;}/*** @param request 请求* @param index   默认第几页* @param size    默认每页记录数量*/public Page(HttpServletRequest request, int index, int size) {pageIndex = getPageIndex(request) == null ? index : Integer.parseInt(getPageIndex(request));pageSize = getPageSize(request) == null ? size : Integer.parseInt(getPageSize(request));start = (pageIndex - 1) * pageSize + 1;end = pageIndex * pageSize;}private static String getPageSize(HttpServletRequest request) {return request.getParameter("pageSize");}private static String getPageIndex(HttpServletRequest request) {return request.getParameter("pageIndex");}public void setQueryCondition(Map map) {map.put("START", start);map.put("END", end);map.put("start", start);map.put("end", end);}/*** 设置查询分页** @param request* @param map*/public static void setQueryByPage(HttpServletRequest request, Map map) {new Page(request).setQueryCondition(map);}/*** 在返回结果中增加页码** @param mv*/public void setReturnValue(ModelAndView mv) {mv.addObject("start", start);}/*** 设置查询尺寸** @param map*/public static void getSize(Map map) {int pageIndex = map.get("pageIndex") == null ? 1 : Integer.parseInt(map.get("pageIndex").toString());int pageSize = map.get("pageSize") == null ? DEFAULT_SIZE : Integer.parseInt(map.get("pageSize").toString());map.put("START", (pageIndex - 1) * pageSize);map.put("END", pageIndex * pageSize - 1);}public int getStart() {return this.start;}public int getEnd() {return this.end;}public int getPageIndex() {return this.pageIndex;}public int getPageSize() {return this.pageSize;}static class PageUtil {static void setPage(HttpServletRequest request, int pageSize, Map queryMap, ModelAndView mv) {Page page = new Page(request, 1, pageSize);page.setQueryCondition(queryMap);page.setReturnValue(mv);}}}