java - 为接口(interface)方法指定抽象或不指定有什么区别？

Question

在 Java 接口(interface)的方法上指定 abstract 关键字和不指定有什么区别？

喜欢:

public void foo();
public abstract void foo();

Answer 1

没有区别。查看 JLS Interfaces - Abstract Method Declatations :

Every method declaration in the body of an interface is implicitly abstract, so its body is always represented by a semicolon, not a block.

另请注意:

For compatibility with older versions of the Java platform, it is permitted but discouraged, as a matter of style, to redundantly specify the abstract modifier for methods declared in interfaces.