Java对List进行分页
Java对组装的List分页
以前一直是在DAO层直接从数据库里分页,但是今天因为有些数据,需要混合展示,就是根据条件取出了多个对象的集合,然后把这些多个List放到一个List里,然后在从这个List里进行分页。
1 public SearchResult paging(List<T> list, int pageNumber, int pageSize) throws Exception{ 2 List<T> pageList = new ArrayList<T>(); 3 int currIdx = (pageNumber > 1 ? (pageNumber -1) * pageSize : 0); 4 for (int i = 0; i < pageSize && i < list.size() - currIdx; i++){ 5 T listNew = list.get(currIdx + i); 6 pageList.add(listNew); 7 } 8 SearchResult<T> searchResult = new SearchResult<>(); 9 searchResult.setList(pageList); 10 searchResult.setTotal(list.size()); 11 if (searchResult.getTotal()%pageSize == 0){ 12 searchResult.setPages((int)searchResult.getTotal()/pageSize); 13 }else { 14 searchResult.setPages((int)searchResult.getTotal()/pageSize + 1); 15 } 16 searchResult.setPageNum(pageNumber); 17 searchResult.setPageSize(pageSize); 18 searchResult.setSize(pageList.size()); 19 //是否是第一页 20 if (pageNumber == 1){ 21 searchResult.setIsFirstPage(true); 22 }else { 23 searchResult.setIsFirstPage(false); 24 } 25 //是否是最后一页 26 if ((searchResult.getTotal() - pageNumber*pageSize) > 0){ 27 searchResult.setIsLastPage(false); 28 }else { 29 searchResult.setIsLastPage(true); 30 } 31 return searchResult; 32 }
hello world!!!