import java.util.ArrayList; 

import java.util.Arrays; 

import java.util.List; 



/** 

 * List -String 互换 

 * @author lenovo 

 * 

 */ 

public class YTest { 


 public static void main(String[] args){ 


 List<String> aa= new ArrayList<String>(); 

 aa.add("a1"); 

 aa.add("a2"); 


 //List-->String 

 String[] cc = (String[]) aa.toArray(new String[aa.size()]); 

 System.out.println(":"+cc[0]+","+cc[1]); 

 //String-->List 

 List<String> bb= Arrays.asList(cc); 

 System.out.println(":"+bb.get(0)+","+bb.get(1)); 

 } 

}