Java abstract interface与 interface的区别

我们常常遇到abstract class与 interface的区别，今天却遇到了abstract interface，感觉interface不用abstract再修饰了啊。结论：事实也确实如此，编译为.class文件后abstract interface成为了interface。

package com.abstractinterface;

public abstract interface DaemonUserSignal
{
  public abstract void signal();
}

package com.abstractinterface;

public interface DaemonUserSignal2
{
  public abstract void signal();
}

编程后结果比较：

D:\git\concurrent_crypto\target\classes\com\abstractinterface>javap DaemonUserSignal.class
Compiled from "DaemonUserSignal.java"
public interface com.abstractinterface.DaemonUserSignal {
  public abstract void signal();
}

D:\git\concurrent_crypto\target\classes\com\abstractinterface>javap DaemonUserSignal2.class
Compiled from "DaemonUserSignal2.java"
public interface com.abstractinterface.DaemonUserSignal2 {
  public abstract void signal();
}