<Sound Dev> [9] Review Request: 8135100 Behavior of null arguments not specified in javax.sound.sampled.spi

[Sergey Bylokhov]

Hello Audio Guru.

Please review the fix for jdk9. This issue is a subtask of:
4912693: Behavior of null arguments not specified in Java Sound

In this patch I cover the whole javax.sound.sampled.spi package.

The small description of the fix:
- I have checked all methods in the spi package and all related methods 
in AudioSystem class.
- I have moved related tests to the folder corresponding the package and 
class name.
- I have written a tests for every method and class which I changed. 
Note that these classes related to the different service providers, so I 
have covered all installed implementations of each provider.


Long description.
I splits the fix to 3 use cases:
- If the method always throw a NPE, then I simply update a javadoc and 
write a small test.
- If the method most of the time throw a NPE then I update a javadoc and 
change the method to always throw a NPE. Also I write a test which tries 
to emulate both cases when NPE was thrown and when not. For example 
AudioFileWriter.isFileTypeSupported(Type) always throws a NPE if at 
least one type is supported, but if the array is empty then false is 
returned.
- If the method have a few parameters and throw a NPE for some set of 
them. For example AudioFloatFormatConverter.
isConversionSupported(Encoding,AudioFormat), the appropriate test tries 
to cover these cases.

It turned out that all methods throw a NPE except of one: 
AudioSystem.getMixer()(MixerProvider.getMixer()), but it was found that 
the specification of MixerProvider.getMixer has no information about the 
null, so I copied it from the AudioSystem.getMixer(). Also one 
implementation of MixerProvider  - PortMixerProvider.getMixer() throws 
NPE, so updated its implementation to the same as 
DirectAudioDeviceProvider.getMixer();

I have done all related regression/jck/sqe tests, and I found one issue 
in jck and regression tests. Both are related to JDK-4941629 [1] (see 
comments in this CR). The jck test assumes that the method 
AudioSystem.write(ais, null, stream) should throw 
IllegalArgumentException. But according to specification it should throw 
IllegalArgumentException if the type is unsupported, but the related 
method  AudioSystem.isFileTypeSupported(Type) will always throw a NPE 
for null. I prefer to file a bug against jck for this case.


[1] https://bugs.openjdk.java.net/browse/JDK-4941629

Bug: https://bugs.openjdk.java.net/browse/JDK-8135100
The new test: http://cr.openjdk.java.net/~serb/8135100/webrev.01

-- 
Best regards, Sergey.