Reads into an array of bytes. If
len
is not zero, the method
blocks until some input is available; otherwise, no
bytes are read and
0
is returned.
Returns:
the actual number of bytes read, or -1 if the end
of the stream is reached.
Parameters:
-
buf - the buffer into which the data is read
-
off - the start offset in the destination array
b
-
len - the maximum number of bytes read
Throws:
-
NullPointerException - If
buf
is
null
.
-
IndexOutOfBoundsException - If
off
is negative,
len
is negative, or
len
is greater than
buf.length - off
-
IOException - if an I/O error has occurred