一段很简单的额代码，但是就是显示有错误
import java.util.*;
public class TestSort
{
public class void main(String [] args)
{
ArrayList al=new ArrayList();
al.add(new Integer(1));
al.add(new Integer(3));
al.add(new Integer(2));
System.out.println(al.toString());
Collection.Sort(al);
System.out.println(al.toString());
}
}

[解决办法]
import java.util.*;
public class TestSort
{
public static void main(String [] args) //static
{
ArrayList al=new ArrayList();
al.add(new Integer(1));
al.add(new Integer(3));
al.add(new Integer(2));
System.out.println(al.toString());
Collections.sort(al); //Collections.sort
System.out.println(al.toString());
}
}