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  1. interface A {
  2.   void doSomethingA1();
  3.   void doSomethingA2();
  4.   void doSomethingA3();
  5. }
  6.  
  7.  
  8. interface B {
  9.   void doSomethingB(); 
  10.   A getA();
  11. }
  12.  
  13.  
  14. interface C {
  15.   void doSomethingC(); 
  16.   A getA();
  17. }
  18.  
  19. interface X {
  20.   A getA();
  21.   B getB();
  22.   C getC();
  23.   void doSomethingX(); 
  24. }
  25.  
  26.  
  27. class AImpl implements A { 
  28.   int x; 
  29.   public void doSomethingA1() { /* ... */ }
  30.   public void doSomethingA2() { /* ... */ }  
  31.   public void doSomethingA3() { /* ... */ }
  32. }
  33.  
  34.  
  35. class BImpl implements B {
  36.   A a;
  37.   public A getA() { return a; }
  38.   public void doSomethingB() { /* ... */ }
  39. }
  40.  
  41. /* если нужно явно имплементировать А (без делегации)
  42. class BImpl implements B, A {
  43.   public A getA() { return this; }
  44.   public void doSomethingA1() { }  
  45.   public void doSomethingA2() { }
  46.   public void doSomethingA3() { }  
  47.   public void doSomethingB() { }
  48. }
  49. */
  50.  
  51. class CImpl implements C {
  52.   A a;
  53.   public A getA() { return a; }
  54.   public void doSomethingC() { /* ... */ }  
  55. }
  56.  
  57. class XImpl implements X {
  58.   B b;
  59.   C c;
  60.  
  61.   public B getB() { return b; }
  62.   public C getC() { return c; }
  63.  
  64.   // нужно явно разрешить diamong problem
  65.   public A getA() { return b.getA(); }  
  66.  
  67.   public void doSomethingX() { /* ... */ }  
  68. }
  69.  
  70.  
  71. class Main {
  72.   public static void main(String[] args) { }
  73.     void usage() {
  74.   	X x = null;  // createX(...)
  75.   	x.doSomethingX();
  76.   	x.getA().doSomethingA1();
  77.   	x.getA().doSomethingA2();
  78.   	x.getA().doSomethingA3();
  79.   	x.getB().doSomethingB();
  80.   	x.getC().doSomethingC();  	
  81.   }
  82.  
  83. }
  84.  
Success #stdin #stdout 0.04s 4575232KB
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https://ideone.com/jS80AN
language:
Java (HotSpot 12)
created:
6 years ago
visibility:
public

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