Why cant a RandomAccessFile be casted to Inputstream?

Question

I get compilation error when I do this cast:

RandomAccessFile raf = new RandomAccessFile(...)
InputStream is = (InputStream)raf;

Rand

Answer 1

RandomAccessFile is supposed to extends InputStream although not directly.

No it isn't. See the Javadoc.

From docs:

RandomAccessFile implements DataInput which in turn DataInputstream & InputStream.

That's not 'from the docs' at all. You made it up. What you've written doesn't even make sense. DataInput is an interface. DataInputStream and InputStream are classes. Interfaces don't implement, or extend, classes.

What the Javadoc actuallys says is that RandomAccessFile extends java.lang.Object and implements Closeable, DataInput, DataOutput.