Hi, Is it possible to extend java.io.File?
I see no reason why not.
javac (through Netbeans) gives me an error:
cannot find symbol:
symbol : constructor File()
location: class java.io.File
class Dir extends java.io.File {
1 error
BUILD FAILED (total time: 5 seconds)
The problem isn't with File, but with your subclass.
You are attempting to call the no-argument constructor of
File, but File doesn't have such a constructor.
You may not have written an explicit call on File's
constructor, either as `new File()' or as `super()' in a
FunnyFile constructor, but remember: a subclass' constructor
cannot start doing its job until its superclass' constructor
has finished. The job of the FunnyFile constructor is to
take an existing File and specialize it; the File itself
is built by File's own constructor. This "constructor
chaining" is so important that if you do not call `super()'
explicitly (perhaps with arguments), the compiler inserts a
no-argument `super()' call on your behalf. And if the
superclass doesn't have a no-argument constructor, as File
doesn't, the no-argument `super()' call won't compile.
Why doesn't the compiler call one of the constructors
File actually has, instead of calling one that doesn't
exist? Well, which of them should it call, and with what
argument values? The compiler cannot read your mind.
