java 类的初始化顺序

public class FatherClass  {public  final int aa= getIntValuea();public FatherClass(){System.out.println("FatherClass construtor");}public  int getIntValuea(){System.out.println("FatherClass getInValue");return 11;}}

public class SubClass extends FatherClass {private int inta= getIntValue();private int intaa= 2;public SubClass(){System.out.println("SubClass construtor");}public static void main(String[] args) {System.out.println("main method");new SubClass();}public int getIntValue(){System.out.println("getInValue");System.out.println(SUB);System.out.println(intaa);return 11;}public   String SUB = "str";}

输出

main method
FatherClass getInValue
FatherClass construtor
getInValue
null
0
SubClass construtor

1、程序首先执行main主线程，打印输出main method
2、new SubClass();时先检查父类，并加载
3、加载类时，先加载static 定义的字段，然后按定义顺序初始化其他字段，最后调用构造函数。
4、最后按三的方法初始化子类