Java 類初始化順序

self_control發表於2015-08-16
Java
Java 類初始化順序為
1、父類靜態欄位初始化
2、子類靜態欄位初始化
3、父類普通欄位初始化
4、父類構造器執行
5、子類普通欄位初始化
6、子類構造器執行

點選(此處)摺疊或開啟

  1. import java.util.Random;

  3. public class InitOrder {
  4.     public static int getInt(String info){
  5.         System.out.println(info);
  6.         Random random = new Random(47);
  7.         return random.nextInt();
  8.     }
  9.     public static void main(String [] args){
  10.         new Son();
  11.         // 關注 Father 的 filed 與 Son 的sonFiled的初始化
  12.     }
  13. }

  15. class Son extends Father{
  16.     private int sonFiled = InitOrder.getInt("子類普通欄位初始化");
  17.     private static int sonStaticFiled = InitOrder.getInt("子類靜態欄位初始化");
  18.     public Son(){
  19.         this.sonFiled = InitOrder.getInt("子類構造器執行");
  20.     }
  21.     public int getSonFiled() {
  22.         return sonFiled;
  23.     }
  24.     public void setSonFiled(int sonFiled) {
  25.         this.sonFiled = sonFiled;
  26.     }
  27.     public static int getSonStaticFiled() {
  28.         return sonStaticFiled;
  29.     }
  30.     public static void setSonStaticFiled(int sonStaticFiled) {
  31.         Son.sonStaticFiled = sonStaticFiled;
  32.     }

  34.     
  35. }
  36. class Father{
  37.     private int filed = InitOrder.getInt("父類普通欄位初始化");
  38.     private static int staticFiled = InitOrder.getInt("父類靜態欄位初始化");
  39.     public Father(){
  40.         this.filed = InitOrder.getInt("父類構造器執行");
  41.     }
  42.     public int getFiled() {
  43.         return filed;
  44.     }
  45.     public void setFiled(int filed) {
  46.         this.filed = filed;
  47.     }
  48.     public static int getStaticFiled() {
  49.         return staticFiled;
  50.     }
  51.     public static void setStaticFiled(int staticFiled) {
  52.         Father.staticFiled = staticFiled;
  53.     }
  54.     
  55. }


來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/30066956/viewspace-1773078/，如需轉載，請註明出處，否則將追究法律責任。

相關文章