In a Java interface each method is by default public
:
Every method declaration in the body of an interface is implicitly abstract, so its body is always represented by a semicolon, not a block.
Every method declaration in the body of an interface is implicitly public. [..]
In an implementing class you are not allowed to reduce the visibility, and by not specifying an access modifier:
void print(){..}
you are specifying the access level default, which has lower visibility than public
.