How to play/record sound on/from a javax.sound.sampled.Line

i have an array filled with the javax.sound.sampled.Line.Info objects of all currently attatched microphones

Info[] sourceInfos = AudioSystem.getSourceLineInfo(Port.Info.MICROPHONE);

Using them i can get the lines of all microphones

for (Info sourceInfo : sourceInfos) {
    Line sourceLine = AudioSystem.getLine(sourceInfo);
    // record sound from those lines
}

Same goes for the speaker

Info[] sourceInfos = AudioSystem.getSourceLineInfo(Port.Info.SPEAKER);
for (Info sourceInfo : sourceInfos) {
    Line sourceLine = AudioSystem.getLine(sourceInfo);
    // play sound on those lines
}

Now i just need to figure out how to play sound on a Line and how to record sound from a Line. This is where i got stuck and couldn't find a solution for.

So just to have it said, the question is, how can i read/write to a line?
Thanks
Baschdi

You can try this example to capture and play audio. It is based on the samples provided in the Java Sound API docs.

Here are the resources you may refer to:

1. Accessing Audio System Resources
2. Capturing audio.

3. Playing audio.

   import java.io.ByteArrayOutputStream;
   import java.io.IOException;
   import javax.sound.sampled.AudioFormat;
   import javax.sound.sampled.AudioInputStream;
   import javax.sound.sampled.AudioSystem;
   import javax.sound.sampled.DataLine;
   import javax.sound.sampled.LineUnavailableException;
   import javax.sound.sampled.Mixer;
   import javax.sound.sampled.SourceDataLine;
   import javax.sound.sampled.TargetDataLine;
   
   public class Audio {
   
   boolean stopCapture = false;
   ByteArrayOutputStream byteArrayOutputStream;
   AudioFormat audioFormat;
   TargetDataLine targetDataLine;
   AudioInputStream audioInputStream;
   SourceDataLine sourceDataLine;
   byte tempBuffer[] = new byte[500];
   
   public static void main(String[] args) {
       Audio audio = new Audio();
       audio.captureAudio();
   
   }
   
   private AudioFormat getAudioFormat() {
       float sampleRate = 8000.0F;
       int sampleSizeInBits = 16;
       int channels = 1;
       boolean signed = true;
       boolean bigEndian = true;
       return new AudioFormat(sampleRate, sampleSizeInBits, channels, signed, bigEndian);
   }
   
   private void captureAudio() {
       try {
   
           /* ~~~~~ UPDATE THIS PART OF CODE ~~~~~*/
   
           Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();    //get available mixers
           System.out.println("Available mixers:");
           for (int cnt = 0; cnt < mixerInfo.length; cnt++) {
               System.out.println(mixerInfo[cnt].getName());
           }
           audioFormat = getAudioFormat();     //get the audio format
   
           DataLine.Info dataLineInfo = new DataLine.Info(TargetDataLine.class, audioFormat);
   
           Mixer mixer = AudioSystem.getMixer(mixerInfo[3]);   //getting the mixer for capture device
   
           /* ~~~~~ UPDATE THIS PART OF CODE ~~~~~*/ 
   
           targetDataLine = (TargetDataLine) mixer.getLine(dataLineInfo);
           targetDataLine.open(audioFormat);
           targetDataLine.start();
   
           DataLine.Info dataLineInfo1 = new DataLine.Info(SourceDataLine.class, audioFormat);
           sourceDataLine = (SourceDataLine) AudioSystem.getLine(dataLineInfo1);
           sourceDataLine.open(audioFormat);
           sourceDataLine.start();
   
           Thread captureAndPlayThread = new captureAndPlayThread();   //thread to capture and play audio
           captureAndPlayThread.start();
   
       } catch (LineUnavailableException e) {
           System.out.println(e);
           System.exit(0);
       }
   }
   
   class captureAndPlayThread extends Thread {
   
       @Override
       public void run() {
           byteArrayOutputStream = new ByteArrayOutputStream();
           stopCapture = false;
           try {
               int readCount;
               while (!stopCapture) {
                   readCount = targetDataLine.read(tempBuffer, 0, tempBuffer.length);  //capture sound into tempBuffer
                   if (readCount > 0) {
                       byteArrayOutputStream.write(tempBuffer, 0, readCount);
                       sourceDataLine.write(tempBuffer, 0, 500);   //playing audio available in tempBuffer
                   }
               }
               byteArrayOutputStream.close();
           } catch (IOException e) {
               System.out.println(e);
               System.exit(0);
           }
       }
   }
   
   }
   

   `

Edit: Please update the previous code with this code. The following code snippet selects a mixer only if it supports microphone i.e, TargetDataLine. Similarly you can do for speakers i.e, SourceDataLine.

        Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();    //get available mixers
        System.out.println("Available mixers:");
        Mixer mixer = null;
        for (int cnt = 0; cnt < mixerInfo.length; cnt++) {
            System.out.println(cnt + " " + mixerInfo[cnt].getName());
            mixer = AudioSystem.getMixer(mixerInfo[cnt]);

            Line.Info[] lineInfos = mixer.getTargetLineInfo();
            if (lineInfos.length >= 1 && lineInfos[0].getLineClass().equals(TargetDataLine.class)) {
                System.out.println(cnt + " Mic is supported!");
                break;
            }
        }

        audioFormat = getAudioFormat();     //get the audio format
        DataLine.Info dataLineInfo = new DataLine.Info(TargetDataLine.class, audioFormat);