Get audio input

Listener.java

package audiosource;

import javax.sound.sampled.*;
import java.io.IOException;
import java.nio.ByteBuffer;

public class Listener {
    public Listener() throws LineUnavailableException {
        audioFormat = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, sampleRate, sampleSize,
                channels, sampleSize / 8 * channels, sampleRate, true);
        DataLine.Info info = new DataLine.Info(TargetDataLine.class, audioFormat);

        if (!AudioSystem.isLineSupported(info)) {
            throw new LineUnavailableException("Line is not supported: " + info.toString());
        }

        line = (TargetDataLine) AudioSystem.getLine(info);
        line.open(audioFormat, line.getBufferSize());
    }

    public float getSampleRate() {
        return sampleRate;
    }

    private final AudioFormat audioFormat;
    private final float sampleRate = 44100.0f;
    private final int channels = 2;
    private final int sampleSize = 16;

    private final TargetDataLine line;
    private AudioInputStream stream;

    public void start() {
        stream = new AudioInputStream(line);
        line.start();
    }

    public double[] stop() throws IOException {
        byte[] buffer = new byte[stream.available()];
        if (stream.read(buffer) != buffer.length) {
            throw new RuntimeException("available and received are not the same :(");
        }

        double[] res = new double[buffer.length / 2];
        for (int i = 0; i < res.length; ++i) {
            res[i] = ByteBuffer.wrap(buffer, i * 2, 2).getShort();
        }

        stream.close();
        line.stop();
        return res;
    }

    public void close() {
        line.close();
    }
}