Reads eight input bytes and returns a double value. It does this by first constructing a long value in exactly the manner of the readLong method, then converting this long value to a double in exactly the manner of the method Double.longBitsToDouble. This method is suitable for reading bytes written by the writeDouble method of interface DataOutput.

Returns:  the double value read.

Exceptions:

EOFException		if this stream reaches the end before reading all the bytes.
IOException		if an I/O error occurs.