1、LinkedHashSet有序链式集合
举例:
long startTime=System.currentTimeMillis(); LinkedHashSet oprTypeSet = new LinkedHashSet(); for(String it : arr) { oprTypeSet.add(it); } Iterator it=oprTypeSet.iterator(); while(it.hasNext()) { System.out.println((String)it.next()); } long endTime=System.currentTimeMillis(); System.out.println("cost---:"+(endTime1-startTime1));