接口

interface CompareA {
    public static final int NUM = 10;

    public abstract void show();

    public default void show2() {
        System.out.println("CompareA show2");
    }
}

interface CompareB {
    public default void show2() {
        System.out.println("CompareB show2");
    }
}

class CompareC implements CompareA, CompareB {
    @Override
    public void show() {
        System.out.println("CompareC show");
    }

    @Override
    public void show2() {
        System.out.println("CompareC show2");
    }
}