read
int read(DS_BYTEHolder b,
int off,
int len)
throws CORBAFileServerException
Reads up to len bytes of data from the input stream into an array
of bytes. An attempt is made to read as many as len bytes, but a
smaller number may be read, possibly zero. The number of bytes
actually read is returned as an integer.
This method blocks until input data is available, end of file
is detected, or an exception is thrown.
If b is null, a NullPointerException is thrown.
If off is negative, or len is negative, or off+len is greater
than the length of the array b, then an IndexOutOfBoundsException is thrown.
If len is zero, then no bytes are read and 0 is returned;
otherwise, there is an attempt to read at least one byte.
If no byte is available because the stream is at end of file,
the value -1 is returned; otherwise, at least one byte is read and stored into b.
The first byte read is stored into element b[off], the next one into b[off+1],
and so on. The number of bytes read is, at most, equal to len. Let k be the number
of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1],
leaving elements b[off+k] through b[off+len-1] unaffected.
In every case, elements b[0] through b[off] and elements b[off+len]
through b[b.length-1] are unaffected.
If the first byte cannot be read for any reason other than end of file,
then an IOException is thrown. In particular, an IOException is thrown
if the input stream has been closed.
The read(b, off, len) method for class InputStream simply calls the method
read() repeatedly. If the first such call results in an IOException,
that exception is returned from the call to the read(b, off, len) method.
If any subsequent call to read() results in a IOException, the exception
is caught and treated as if it were end of file; the bytes read up to that
point are stored into b and the number of bytes read before the exception
occurred is returned. Subclasses are encouraged to provide a more efficient
implementation of this method.
- Parameters:
b - - the buffer into which the data is read.off - - the start offset in array b at which the data is written.len - - the maximum number of bytes to read.- Returns:
- the total number of bytes read into the buffer,
or -1 is there is no more data because the end
of the stream has been reached.
- Throws:
CORBAFileServerException - if an IO exception occurs.