深入理解final变量的初始化

public class InitOrder {
    {
        System.out.println("before---field");
        //System.out.println("d1="+d1);
        d1 = 3;
        //System.out.println("d1="+d1);
    }
    static {
        System.out.println("before---static field");
        //System.out.println("d2="+d2);
        d2 = 3;
        //System.out.println("d2="+d2);
    }
    final int a1 = 1;
    final int b1;
    final int c1;
    final int d1;
    //final int e1;
    static final int a2 = 1;
    //static final int b2;
    static final int c2;
    static final int d2;
    //static final int e2;

    {
        System.out.println("after---field");
        //System.out.println("c1="+c1);
        c1 = 4;
        System.out.println("c1="+c1);
        //e2 =3;
    }
    static {
        System.out.println("after---static field");
        //System.out.println("c2="+c2);
        c2 = 4;
        System.out.println("c2="+c2);
        //e1 = 3;
    }
    public InitOrder() {
        b1 = 2;
        //b2 = 2;
    }
    public static void main(String[] args) {
        InitOrder order = new InitOrder();
        System.out.println("c1="+order.c1);
        System.out.println("c2="+order.c2);
        System.out.println("d1="+order.d1);
        System.out.println("d2="+order.d2);
    }
}