java - 如果两个接口(interface)包含相同的默认方法会怎样？

Question

如果我有两个具有相同默认方法的接口(interface)，并且都使用一个类来实现/请参阅此程序。

interface alpha {
  default void reset() {
    System.out.println("This is alpha version of default");
  }
}

interface beta {
  default void reset() {
    System.out.println("This is beta version of default");
  }
}

class MyClass implements alpha, beta {
  void display() {
    System.out.println("This is not default");
  }
}

class main_class {
  public static void main(String args[]) {
    MyClass ob = new MyClass();
    ob.reset();
    ob.display();
  }  
}

然后会发生什么？而且我还遇到了与该程序无关的错误。

Answer 1

You cannot implement multiple interfaces having same signature of Java 8 default methods (without overriding explicitly in child class)

.您可以通过实现方法来解决它，例如

class MyClass implements alpha, beta {
  void display() {
    System.out.println("This is not default");
  }

  @Override
  public void reset() {
    //in order to call alpha's reset
    alpha.super.reset();
    //if you want to call beta's reset 
    beta.super.reset();

  }
}