list删除指定元素
方法1:

for(int i=0,len=list.size();i<len;++i){ 
 if(list.get(i)==XXX){ 
 list.remove(i); 
 --len;
 }




方法2:

Iterator<String> sListIterator = list.iterator(); 
 while(sListIterator.hasNext()){ 
 String e = sListIterator.next(); 
 if(e.equals("3")){ 
 sListIterator.remove(); 
 }
 }




list删除重复元素
方法1:

List list = new ArrayList();
 list.add(0,"1");
 list.add(1,"2");
 list.add(2,"2");
 list.add(3,"3");
 for( int i=0;i<list.size()-1;i++ ){
 for(int j=list.size()-1;j>i;j--){
 if(list.get(j).equals(list.get(i))){
 list.remove(j);
 }
 }
 }
 System.out.println(list);



方法2:

HashSet h=new HashSet(list);
 list.clear();
 list.addAll(h);
 System.out.println(list);



方法3:

Set set=new HashSet();
 List newList=new ArrayList();
 for(Iterator iter=list.iterator();iter.hasNext();){
 Object element=iter.next();
 if(set.add(element))
 newList.add(element);
 }
 list.clear();
 list.addAll(newList);
 System.out.println(list);