package Multithreading; import java.util.*; public class BuyTicketDemo { public static void main(String[] args) { StringBuffer sb = new StringBuffer(); StringBuilder sb2= new StringBuilder(); Vector<String> v= new Vector<String>(); ArrayList<String> arrayList = new ArrayList<String>(); Hashtable<String,String> hs= new Hashtable<String,String>(); HashMap<String,String> hs2 = new HashMap<String,String>(); List<String> list = Collections.synchronizedList(new ArrayList<String>()); } }