Java 初始化及类的加载

下面是Think in Java中的一段代码，自己加了几行

package reusing;

import static net.mindview.util.Print.*;

class Insect {
private int i = 9;
protected int j;

private int x2 = printInit("Insect.x1 initialized");

Insect() {
print("i = " + i + ", j = " + j);
j = 39;
}
static {
System.out.println("Init Static block");
}

{
System.out.println("Init block");
}

private static int x1 = printInit("static Insect.x1 initialized");

static int printInit(String s) {
print(s);
return 47;
}
}

public class Beetle extends Insect {
private int k = printInit("Beetle.k initialized");

static {
System.out.println("Beetle static block");
}

public Beetle() {
print("k = " + k);
print("j = " + j);
}

private static int x2 = printInit("static Beetle.x2 initialized");
private int x1 = printInit("Beetle.x2 initialized");

public static void main(String[] args) {
print("Beetle constructor");
Beetle b = new Beetle();
}

}

分析其类加载的过程：

         （1）首先加载当前类，再加载当前类的父类，直到加载到基类，然后执行基类的static代码块，再执给基类里面的static成员变量赋值，赋值完成之后再执行子类里面的static代码块和给static成员变量赋值，以此类推。

（2）static块和成员赋值为完成之后回到基类中，给其余的非static的成员变量赋值，再执行非静态块，然后是构造方法，完成之后回到子类中继续按（2）处执行

上面的代码执行结果是：

Init Static block

static Insect.x1 initialized

Beetle static block

static Beetle.x2 initialized

Beetle constructor

Insect.x1 initialized

Init block

i = 9, j = 0

Beetle.k initialized

Beetle.x2 initialized

k = 47

j = 39