将list分成多个list集合
1:按指定大小,分隔集合,将集合按规定个数分为n个部分
/** * 将集合按len数量分成若干个list * @param list * @param len 每个集合的数量 * @return */ public static List<List<TotalorderDO>> splitList(List<TotalorderDO> list, int len) { if (list == null || list.size() == 0 || len < 1) { return null; } List<List<TotalorderDO>> result = new ArrayList<List<TotalorderDO>>(); int size = list.size(); int count = (size + len - 1) / len; for (int i = 0; i < count; i++) { List<TotalorderDO> subList = list.subList(i * len, ((i + 1) * len > size ? size : len * (i + 1))); result.add(subList); } return result; }
2:将一个list均分成n个list
/** * @param list * @return */ public static <T> List<List<T>> averageAssign(List<T> list,int n){ List<List<T>> result=new ArrayList<List<T>>(); int remaider=list.size()%n; //(先计算出余数) int number=list.size()/n; //然后是商 int offset=0;//偏移量 for(int i=0;i<n;i++){ List<T> value=null; if(remaider>0){ value=list.subList(i*number+offset, (i+1)*number+offset+1); remaider--; offset++; }else{ value=list.subList(i*number+offset, (i+1)*number+offset); } result.add(value); } return result; }