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();
}
}
