jvm加载类 对象

1、加载源代码。父类->基类
2、分配静态成员变量并进行默认初始化；调用静态初始化代码块进行显式初始化。基类->父类
3、分配成员变量并进行默认初始化；调用构造方法进行显式初始化。基类->父类
注：第1和2步骤加载类，第3步骤加载对象；加载对象时，查看对应的类是否已加载，是则加载对象，否则，先加载类，再加载对象。

 

class Base {
	protected static String str;

	protected static void printStr() {
		System.out.println(str);
	}

	static {
		printStr();
		str = "[static block]:Base!";
	}

	public Base() {
		printStr();
		str = "[construct block]:Base!";
	}
}

public class Derived extends Base {
	static {
		printStr();
		str = "[static block]:Derived!";
	}

	public Derived() {
		printStr();
		str = "[construct block]:Derived!";
	}

	public static void main(String[] args) {
		new Derived();
		printStr();
	}
}