public class Page implements Serializable { private static final long serialVersionUID = 1L; public Page(int pageSize, int pageNum) { if(pageSize > 0 ){ this.pageSize = pageSize; } if(pageNum > 0){ this.pageNum = pageNum; } } /** * 初始化各个值 */ public void initValue(){ // 计算总共有多少页 totlePages = (int)Math.ceil(totleElements * 1.0 / pageSize); if(totlePages == 0){ totlePages = 1; } // 页码矫正 if(pageNum <= 0){ pageNum = 1; } if(pageNum > totlePages){ pageNum = totlePages; } // 是否有上一页和首页 if(pageNum > 1){ hasPrevious = true; prePage = pageNum - 1; } // 是否有下一页和尾页 if(totlePages > pageNum){ hasNext = true; nextPage = pageNum + 1; } // 分页页码开始数值 begin = Math.max(1, pageNum - paginationSize/2); // 分页页码结束数值 end = Math.min(begin + (paginationSize - 1), totlePages); } /** * 分页下标最多显示多少页 */ private int paginationSize = 10; /** * 页码开始 */ private int begin = 1; /** * 页码结束 */ private int end = 1; /** * 每页显示多少条 */ private int pageSize = 15; /** * 当前页码 */ private int pageNum = 1; /** * 是否有下一页 */ private boolean hasNext = false; /** * 是否有上一页 */ private boolean hasPrevious = false; /** * 下一页的页码 */ private int nextPage; /** * 上一页的页码 */ private int prePage; /** * 总页数 */ private int totlePages = 1; /** * 总条数 */ private int totleElements = 0; public static int maxNum = 999999; public int getPaginationSize() { return paginationSize; } public void setPaginationSize(int paginationSize) { this.paginationSize = paginationSize; } public int getBegin() { return begin; } public void setBegin(int begin) { this.begin = begin; } public int getEnd() { return end; } public void setEnd(int end) { this.end = end; } public int getPageSize() { return pageSize; } public void setPageSize(int pageSize) { this.pageSize = pageSize; } public int getPageNum() { return pageNum; } public void setPageNum(int pageNum) { this.pageNum = pageNum; } public boolean isHasNext() { return hasNext; } public void setHasNext(boolean hasNext) { this.hasNext = hasNext; } public boolean isHasPrevious() { return hasPrevious; } public void setHasPrevious(boolean hasPrevious) { this.hasPrevious = hasPrevious; } public int getNextPage() { return nextPage; } public void setNextPage(int nextPage) { this.nextPage = nextPage; } public int getPrePage() { return prePage; } public void setPrePage(int prePage) { this.prePage = prePage; } public int getTotlePages() { return totlePages; } public void setTotlePages(int totlePages) { this.totlePages = totlePages; } public int getTotleElements() { return totleElements; } public void setTotleElements(int totleElements) { this.totleElements = totleElements; // 知道总条数之后，初始化一下其它值 initValue(); } public static void main(String[] args) { System.out.println(Math.min(1, 2)); } /** * 从第几条开始查询 * @return */ public int getStartNum(){ return (pageNum -1) * pageSize + 1; } /** * 到第几条结束 * @return */ public int getEndNum(){ return pageNum * pageSize; } }
PageUtil.java （分页辅助类）
public class PageUtil implements Serializable { private static final long serialVersionUID = 1L; /** * 获取目标页码 * @return */ public static int getTargetPage(ServletRequest request){ int pageNum = 0; String pageNumStr = request.getParameter("pageNum"); if(StringUtils.isNotBlank(pageNumStr)){ try{ pageNum = Integer.valueOf(pageNumStr); }catch(Exception e){ pageNum = 0; } } return pageNum; } /** * 获取每页条数 * @return */ public static int getPageSize(ServletRequest request){ int pageSize = 0; String pageSizeStr = request.getParameter("pageSize"); if(StringUtils.isNotBlank(pageSizeStr)){ try{ pageSize = Integer.valueOf(pageSizeStr); }catch(Exception e){ pageSize = 0; } } return pageSize; } /** * 将Map中的查询条件，加上前缀，以&拼接 * @param map * @param prefix 每个参数的前缀 * @return */ public static String encodeParameterStringWithPrefix(Map<String,Object> map, String prefix){ if(null == map || map.isEmpty()){ return ""; } StringBuffer sb = new StringBuffer(); Iterator<Map.Entry<String,Object>> entries = map.entrySet().iterator(); while (entries.hasNext()) { if(StringUtils.isNotEmpty(sb.toString())){ sb.append("&"); } Map.Entry<String,Object> entry = entries.next(); sb.append(prefix); sb.append(entry.getKey()); sb.append("="); sb.append(entry.getValue()); } return sb.toString(); } }
jsp页面中查询条件参数编写示例如下：