On Fri, 2 Jul 2021 17:40:08 GMT, Brian Burkhalter <[email protected]> wrote:
>> src/java.base/share/classes/java/io/ByteArrayInputStream.java line 161:
>>
>>> 159: * Unlike the {@link InputStream#read(byte[],int,int) overridden
>>> method}
>>> 160: * of {@code InputStream}, this method returns {@code -1} instead
>>> of zero
>>> 161: * if the end of the stream has been reached and {@code len == 0}.
>>
>> The statement "return -1 if the end of the stream has been reached and len
>> == 0" gives an impression that it requires both conditions to be met: end of
>> the stream && len==0, but the tests show -1 is expected if len == 0 without
>> an attempt to read the stream.
>>
>> The overridden method stated that "If len is zero, then no bytes are read
>> and 0 is returned", the above note looks like was meant for this statement
>> since the overridden method also return -1 if the stream is at end of file.
>
> Both conditions of the statement are intended to be met. If the stream is at
> its end then
>
> if (pos >= count) {
> return -1;
> }
>
> will cause `-1` to be returned because at end of stream the condition `pos >=
> count` is met.
>
> The overridden method always returns `0` if `len == 0`.:
>
>
> public int read(byte b[], int off, int len) throws IOException {
> Objects.checkFromIndexSize(off, len, b.length);
> if (len == 0) {
> return 0;
> }
Right. I understand. The intention was, unlike the overridden method that
returns 0 if len == 0 and -1 if at the end of the stream, this method returns
-1 in both cases. A careful reader, after comparing both methods, would
understand correctly that the difference is in the case of "len==0". I'm fine
if you think this is good enough. Just a thought though that the statement
could be interpreted as if both conditions need to be met at the same time (if
"and" is taken as "&&", e.g. if (pos>==count && len==0) ).
Something like the following might be clearer?
* Unlike the {@link InputStream#read(byte[],int,int) overridden method}
* of {@code InputStream} that returns {@code -1} if the end of the stream
* has been reached and {@code 0} if {@code len == 0}, this method returns
* {@code -1} in both cases.
Just my 2 cents.
-------------
PR: https://git.openjdk.java.net/jdk17/pull/189
