???????????????
????1??Collection???÷???
Collection coll=new ArrayList();
Collection coll2=new ArrayList();
Object[] a = {new Integer(1)};
//????????
boolean b = coll.add("123");//??????
boolean b1 = coll.remove("123");//??????
//???????
int i = coll.size();//????????????????????
boolean b2 = coll.isEmpty();//?ж????????????κ????
boolean b3 = coll.contains("123");//?????????????ж???"123"
Iterator ite = coll.iterator();//???????????????????????????е???????
//?????
boolean b4 = coll.containsAll(coll2);//?????????????м???coll2?????????
boolean b5 = coll.addAll(coll2);//??????coll2??????????????ü???
coll.clear();//????????????????
boolean b6 = coll.removeAll(coll2);//??????????????coll2?е????????
boolean b7 = coll.retainAll(coll2);//??????????????coll2?в??????????
//Collection????Object????
Object[] obj = coll.toArray();//??????????????????????array
//??????????????????????array????????????array?????a???????????????????????
Object[] obj1 = coll.toArray(a);
????2??List??????÷?
????List????÷???
List list = new ArrayList();
//??????
list.add(1);
//??2????????
list.add(2?? 1);
//??????
list.addAll(new ArrayList());
//??3????????
list.addAll(3??new ArrayList());
//???1???????
Object obj = list.get(1);
//???????"1"????γ????λ?????????-1
int i= list.indexOf(1);
//???????"1"????γ????λ?????????-1
int j= list.lastIndexOf(1);
//???2λ??????
list.remove(2);
//??1?????????"2"
list.set(1?? 2);
????List?????÷???
List list = new ArrayList();
//????????б?????????????????б??е????
ListIterator listIterator = list.listIterator();
//????????б?????????????????λ??2????????б??е????
ListIterator listIterator2 = list.listIterator(2);
//??1??????????2????????????Χ?и????????б????
List subList = list.subList(1?? 2);
????LinkedList???????÷???
//???????????????б?
LinkedList list = new LinkedList();
//???????????????б????????????list?????????
LinkedList list1 = new LinkedList(list);
//??????1????б?????addLast()?????
list.addFirst(1);
//???????????getLast()??ú???????
Object obj = list.getFirst();
//????????????removeLast()???????????
list.removeFirst();
????ArrayList???????÷???
ArrayList list = new ArrayList();
//??ArrayList????????????5
list.ensureCapacity(5);
//????ArrayList??????????б?????С?????????????????????ArrayList????洢???.
????list.trimToSize();
????tips?????????set??map????????????