已閱讀這個問題In what order are the different parts of a class initialized when a class is loaded in the JVM?和相關的JLS。我想更詳細地知道爲什麼例如,具有類動物(父)和Dog類(子類)如下:靜態塊實例塊java訂購
class Animal
{
static{
System.out.println("This is Animal's static block speaking"):
}
{
System.out.println("This is Animal's instance block speaking");
}
class Dog{
static{
System.out.println("This is Dog's static block speaking");
}
{
System.out.println("This is Dog's instance block speaking");
}
public static void main (String [] args)
{
Dog dog = new Dog();
}
}
好的實例化一個類的直接超類之前需要進行初始化(因此所有的靜變量和塊需要被執行)。 所以基本上問題是:爲什麼在初始化超類的靜態變量和靜態塊後,控制下降到靜態變量初始化的子類,而不是完成實例成員的初始化?
控制是這樣:
superclass (Animal): static variables and static blocks
subclass (Dog): static variables and static blocks
superclass (Animal): instance variables and instance blocks
sublcass (Dog):instance variables and instance blocks
的原因是什麼,爲什麼是這樣而不是:
superclass -> static members
superclass -> instance members
subclass -> static members
sublcass-> instance members
我竭力想出這個地方甚至會事(假定超不知道的子類的任何東西)的例子。 – NPE 2013-03-06 17:49:53