import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class Test {

     List list  =   new  LinkedList();
     public   static   void  main(String[] args)  {
        List list  =   new  LinkedList();
         for  ( int  i  =   0 ; i  <   9 ; i ++ )  {
            list.add( " a " + i);
        } 
        Collections.sort(list); // 順序排列 
        System.out.println(list);
        
        Collections.shuffle(list); // 混亂的意思 
        System.out.println(list);
        
        Collections.reverse(list); // 倒序排列 
        System.out.println(list);
        
        System.out.println(Collections.binarySearch(list,  " a5 " )); // 折半查詢 
    } 
    
}