去除List中重复数据
/** * 去除List中重复数据 * @author wjcom * @Date 2010-12-22 * @version [版本号] * @see [相关类/方法] * @since [产品/模块版本] */public class test{/** * @param args */public static void main(String[] args){Long[] initData = {1l, 10l,15l,1l,15l};//方法一List<Object> list1 = deleteRepeatIds1(initData);for (int i = 0; i < list1.size(); i++){System.out.println(list1.get(i));}System.out.println("==================");//方法二List list2 = deleteRepeatIds2(initData);for (int j=0;j<list2.size();j++){System.out.println(list2.get(j));}System.out.println("==================");//方法三：最简洁的方法List list3 = deleteRepeatIds3(initData);for (int k=0;k<list3.size();k++){System.out.println(list3.get(k));}}/** * 方法一 * @param ids * @return */private static List<Object> deleteRepeatIds1(Long[] ids){List<Long> list = new ArrayList<Long>();for (int j = 0; j < ids.length; j++){list.add(ids[j]);}Set<Object> set = new HashSet<Object>();List<Object> newList = new ArrayList<Object>();for (Iterator iter = list.iterator(); iter.hasNext();){Object element = iter.next();if (set.add(element))newList.add(element);}list.clear();return newList;}/** * 方法二 * @param ids * @return */private static List deleteRepeatIds2(Long[] ids){List<Long> list = new ArrayList<Long>(); for (int j = 0; j < ids.length; j++){boolean bl1 = true;boolean bl2 = false;if (list.size()>0){for (int i = 0;i<list.size();i++){if (list.get(i).equals(ids[j])){bl2 = true;}}bl1 = false;}if (bl1 || (!bl1 && !bl2)){list.add(ids[j]);}}return list;}/** * 方法三 * 最简洁的方法 * @param ids * @return */private static List deleteRepeatIds3(Long[] ids){List<Long> list = new ArrayList<Long>();for (int j = 0; j < ids.length; j++){if (!list.contains(ids[j])){list.add(ids[j]);}}return list;}}