Java的動態綁定、靜態綁定和this、super

/** * @author Liu Liu * */ public class JavaObjectTest { /** * @param args */ public static void main(String[] args) { A c_a = new C(); System.out.println("------------"); c_a.second(); System.out.println("------------"); c_a.first(); } } class A { protected int i = 0;//private public A() { System.out.println("A initial"); i = 1; } public void first() { System.out.println("A first"); } public void second() { System.out.println("A second"); System.out.println("A i=" + this.i); } } class B extends A { private int i = 0; public B() { System.out.println("B initial"); i = 2; } public void first() { System.out.println("B first"); super.first(); if(i++ > 2) return; this.first(); } public void second() { System.out.println("B second"); super.second(); System.out.println("B i=" + this.i); System.out.println("super i=" + super.i); } } class C extends B { private int i = 0; public C() { System.out.println("C initial"); i = 3; } public void first() { System.out.println("C first"); super.first(); } // public void second() { // System.out.println("C second"); // super.second(); // System.out.println("C i=" + this.i); // } }

 

輸出如下：

第一部分是初始化順序

第二部分是方法動態綁定的過程

第三部分是this在動態和靜態綁定中的具體含義有所不同。尤其是B中this.first實際上調用C的first，很經典的實例，分享。

 

A initial
B initial
C initial
------------
B second
A second
A i=1
B i=2
super i=1
------------
C first
B first
A first
C first
B first
A first