java的Constructor和static块

public class demo988
{
public static void main(String args[])
{
A a = new B();
System.out.println();
a = new B();

}
}
class A{
static{
System.out.print(1);
}
public A(){
System.out.print(2);
}
}
class B extends A{
static{
System.out.print("a");
}
public B(){
System.out.print("b");
}
}