Deflater enhancements

[Stephen Colebourne]

See
https://bugs.openjdk.java.net/browse/JDK-8026127
https://bugs.openjdk.java.net/browse/JDK-8026128

Stephen


On 8 October 2013 21:33, Xueming Shen <xueming.shen at oracle.com> wrote:
> The 100 in sample really means a "big enough" buffer here for simple use
> case, not
> necessarily means a "fixed size' buffer. Sure there is always room for doc
> improvement,
> especially given this is the API has been there for decade.
>
> Deflater/Inflater.end() is for explicitly/proactively release of the memory
> resource
> held by the deflater/inflater, it does not have impact to the
> deflating/inflating result.
> the end() will be invoked by the finalizer.
>
> It might be reasonable to simply have a pair of static utility methods
>
> byte[] Deflater.deflate(byte[]);
> byte[] Inflater.deflate(byte[]);
>
> For the casual/simple/easy use scenario.
>
> Sherman
>
>
> On 10/08/2013 03:24 AM, Stephen Colebourne wrote:
>>
>> I've been trying to use Deflater today and found it rather tricky. Two
>> thoughts...
>>
>> 1) The class level Javadoc specifies a fixed size byte array of 100.
>> http://download.java.net/jdk8/docs/api/java/util/zip/Deflater.html
>>
>> > From what I can tell from other searching and basic common sense, this
>> cannot be right as the output size could well be bigger than 100.
>> However, there is no real information in the Deflater class as to how
>> the class is supposed to be used. I don't believe that kind of broken
>> example is helpful.
>>
>> The best I found was
>> http://java.dzone.com/articles/how-compress-and-uncompress
>> which proposed a loop:
>> Deflater deflater = new Deflater();
>> deflater.setInput(data);
>> ByteArrayOutputStream outputStream = new
>> ByteArrayOutputStream(data.length);
>> deflater.finish();
>> byte[] buffer = new byte[1024];
>> while (!deflater.finished()) {
>>   int count = deflater.deflate(buffer); // returns the generated code...
>> index
>>   outputStream.write(buffer, 0, count);
>> }
>> outputStream.close();
>> byte[] output = outputStream.toByteArray();
>>
>> Neither example call deflater.end(), which I believe to be a mistake as
>> well.
>>
>> Is my analysis correct? Should I raise a bug for better documentation?
>> (this appears to affect Inflater as well)
>>
>> 2) Even with the Javadoc change, the API is still far too complex.
>>
>> As a user, all I want is something like:
>>   byte[] compressed = Deflater.deflate(input, options...)
>> and similar for Inflater.
>>
>> (I actually want to compress a String, and an override to handle that
>> would be useful as well)
>>
>> Any thoughts on adding a convenience method to make the API a lot
>> easier? Can I raise a bug for that?
>>
>> Stephen
>
>