Java Sound API. Getting supported audio formats from mixer

Question

I'm trying to get a line from an external mixer connected to my pc via USB. So I wrote a simple program to list all the mixers and their respective source lines (outputs) and target lines (inputs), and it works properly:

import javax.sound.sampled.*;

public class TestResources {
    public static void main(String args[]) {
        try {
            Mixer.Info [] mixers = AudioSystem.getMixerInfo();
            for(int i = 0 ; i< mixers.length; i ++) {
                System.out.println((i+1)+". " + mixers[i].getName() + " --> " + mixers[i].getDescription() );

                Line.Info [] sourceLines = AudioSystem.getMixer(mixers[i]).getSourceLineInfo();
                System.out.println("\tSource Lines:" );
                for(int j = 0; j< sourceLines.length; j++) {
                    System.out.println("\t" + (j+1) + ". " + sourceLines[j].toString() );
                }
                System.out.println();

                Line.Info [] targetLines = AudioSystem.getMixer(mixers[i]).getTargetLineInfo();                 
                System.out.println("\tTarget Lines:" );
                for(int j = 0; j< targetLines.length; j++) {
                    System.out.println("\t" + (j+1) + ". " + targetLines[j].toString() );

                }       
                System.out.println("\n" );
            }           
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }
}

However when I actually try to get the line I need like this:

    AudioFormat format = new AudioFormat(44100, 16, 2, true, true);
    Mixer.Info [] mixers = AudioSystem.getMixerInfo();
    final TargetDataLine microphone = AudioSystem.getTargetDataLine(format, mixers[2]);

I get an error saying that the format is not supported by the line:

java.lang.IllegalArgumentException: Line unsupported: interface TargetDataLine supporting format PCM_SIGNED 44100.0 Hz, 16 bit, stereo, 8 bytes/frame, big-endian

How can the initial program be expanded to print the supported formats of each line? Thanks in advance.

Answer 1

This method prints the formats supported by a Line.Info object:

static void showLineInfoFormats(final Line.Info lineInfo)
{
  if (lineInfo instanceof DataLine.Info)
   {
     final DataLine.Info dataLineInfo = (DataLine.Info)lineInfo;

     Arrays.stream(dataLineInfo.getFormats())
           .forEach(format -> System.out.println("    " + format.toString()));
   }
}