java初始化块

class Root{
    static{
        System.out.println("Root的静态初始化块");
    }

    {

        System.out.println("Root的初始化块");
    }
    public Root()
    {
        System.out.println("Root的构造器");
    }
}
class Mid extends Root{
    static{
        System.out.println("Mid的静态初始化块");
    }
    {
        System.out.println("Mid的初始化块");
    }
    public Mid(){
        System.out.println("Mid的构造器");
    }
    public Mid(String msg)
    {
        this();
        System.out.println("消息是："+msg);
    }
}
class Leaf extends Mid{
    static{
        System.out.println("Leaf的静态初始化块");
    }
    {

        System.out.println("Leaf的初始化块");
    }
    public Leaf()
    {
        super("Hi");
        System.out.println("Leaf的构造函数");
    }

}
public class Hello {
    public static void main(String[] args)
    {
        //System.out.println("Hello world");
        new Leaf();
        new Leaf();



    }
}
运行结果如下：
Root的静态初始化块
Mid的静态初始化块
Leaf的静态初始化块
Root的初始化块
Root的构造器
Mid的初始化块
Mid的构造器
消息是：Hi
Leaf的初始化块
Leaf的构造函数
Root的初始化块
Root的构造器
Mid的初始化块
Mid的构造器
消息是：Hi
Leaf的初始化块
Leaf的构造函数