集合转换 java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.Map.Entry;


public class List_Set_Map {


private String a="aaa";
private String b="bbb";
private String c="ccc";
public void list(){
//list 转set 
List list=new ArrayList();
list.add(a);
list.add(b);
list.add(c);
Iterator it=list.iterator();
while(it.hasNext()){
System.out.println(it.next()+"ssssssss");
}