Name: dkR10031 Date: 03/05/2003



The current reference implementation (JDK 1.4.2beta, build b17)
of the javax.sound.sampled.Mixer.open() throws unspecified
NullPointerException when computer has not an audio device.
Note, that prior to JDK 1.4.2beta build 12 LineUnavailableException was
thrown.

The J2SE specification does not specify NullPointerException for this
method. However, LineUnavailableException is specified if the line cannot
be opened due to resource restrictions:
"
open()
....
LineUnavailableException - if the line cannot be opened due to resource
restrictions.
...
"

This behavior seems quite questionable.

This bug causes failure of JCK test:
api/javax_sound/sampled/Mixer/index.html#open[open001].

To reproduce the bug run the following test with JDK build 1.4.2-beta-b17:
------------------ example code begin --------------------------
import javax.sound.sampled.*;

public class MyMixer {
    public static void main(String args[]) {
        Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();
        for( int i=0; i<mixerInfo.length; i++ ) {
            Mixer testedMixer = null;
            try {
                testedMixer = AudioSystem.getMixer(mixerInfo[i]);
                System.out.println(mixerInfo[i]);
                testedMixer.open();
            } catch (NullPointerException npe) {
                System.out.println("NPE:" + npe.getMessage());
            } catch (LineUnavailableException ule) {
                System.out.println("ULE:" + ule.getMessage());
            }
        }
    }
}
------------------ example code end ----------------------------
------------------ JDK 1.4.2beta build 17 log begin ------------
bash-2.03$ uname -a
SunOS novo148 5.8 Generic_108528-18 sun4u sparc SUNW,Ultra-80
bash-2.03$ /export/ld25/java/dest/jdk1.4.2-b17/solaris-sparc/bin/java -showversion MyMixer
java version "1.4.2-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-beta-b17)
Java HotSpot(TM) Client VM (build 1.4.2-beta-b17, mixed mode)

Java Sound Audio Engine, version 1.0
ULE:Audio Device Unavailable
SolarisOS,dev/audio,multi threaded, version Unknown Version
NPE:null
------------------ JDK 1.4.2beta build 17 log end --------------
------------------ JDK 1.4.2beta build 11 log begin ------------
bash-2.03$ uname -a
SunOS novo148 5.8 Generic_108528-18 sun4u sparc SUNW,Ultra-80
bash-2.03$ /export/ld25/java/dest/jdk1.4.2-b11/solaris-sparc/bin/java -showversion MyMixer
java version "1.4.2-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-beta-b11)
Java HotSpot(TM) Client VM (build 1.4.2-beta-b11, mixed mode)

Java Sound Audio Engine, version 1.0
ULE:Audio Device Unavailable
SolarisOS,dev/audio,multi threaded, version Unknown Version
ULE:Unexpected Error
------------------ JDK 1.4.2beta build 11 log end --------------

======================================================================
###@###.### 2003-08-13
Nither ULE or NPE thrown when running test on version 1.5.0-beta-b10.