think in java 第5章 完整的JAVA初始化规则

package think.in.exercise11;

/**

 * @author Administrator

 *				完整展示JAVA的初始化顺序

 *		1:递归寻找顶层基类

 *		2:静态成员初始化

 *		3:静态块初始化

 *		4:成员变量按先后顺序初始化

 *		5:顶层基类的构造方法主体

 *		6:下层子类的构造,重复2~6的执行步骤

 */

class Meal{	

	private String first = getFirst();

	private String second = getSecond();

	private static String zero = getZero();//静态成员放在前的成员后面，但最先执行

	

	public Meal(){

		System.out.println("4:Meal()基类构造方法调用");

	}

	static{//静态块

		System.out.println("3:Meal()基类静态块初始化");		

	}

	private static String getZero(){

		System.out.println("0:静态成员变量最先初始化");

		return "zero";		

	}

	private String getFirst(){

		System.out.println("1:按顺序初始化非静态成员变量 first");

		return "first";

	}

	private String getSecond(){

		System.out.println("2:按顺序初始化非静态成员变量 second");

		return "second";

	}

}

class Bread{

	public Bread(){

		System.out.println("Bread()");

	}

}

class Cheese{

	public Cheese(){

		System.out.println("Cheese()");

	}

}

class Lettuce{

	public Lettuce(){

		System.out.println("Lettuce()");

	}

}

class Lunch extends Meal{

	public Lunch(){

		System.out.println("Lunch()");

	}

}



class PortableLunch extends Lunch{

	public PortableLunch(){

		System.out.println("PortableLunch()");

	}

}



public class Sandwich extends PortableLunch{



	private Bread b = new Bread();

	private Cheese c = new Cheese();

	private Lettuce l = new Lettuce();

	public Sandwich(){

		System.out.println("Sandwich()");

	}

	public static void main(String[] args) {

		// TODO Auto-generated method stub

			new Sandwich();

	}



}