Why is eclipse restricted from here

Question

I thoroughly looked through docs and such but could not find an answer. The problem is that I am trying to make Java play a .mp3 file. The thing is though, eclipse keeps coming up with:

Access restriction: The type LineListener is not accessible due to
restriction on required library /usr/lib/jvm/java-8-openjdk-amd64/jre/lib/rt.jar

This is my code:

    package net.codejava.sound;

import java.io.File;
import java.io.IOException;

import javax.*;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineEvent;
import javax.sound.sampled.LineListener;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;

/**
 * This is an example program that demonstrates how to play back an audio file
 * using the Clip in Java Sound API.
 * @author www.codejava.net
 *
 */
public class Sound implements LineListener {

/**
 * this flag indicates whether the playback completes or not.
 */
boolean playCompleted;

/**
 * Play a given audio file.
 * @param audioFilePath Path of the audio file.
 */
void play(String audioFilePath) {
    File audioFile = new File(audioFilePath);

    try {
        AudioInputStream audioStream = AudioSystem.getAudioInputStream(audioFile);

        AudioFormat format = audioStream.getFormat();

        DataLine.Info info = new DataLine.Info(Clip.class, format);

        Clip audioClip = (Clip) AudioSystem.getLine(info);

        audioClip.addLineListener(this);

        audioClip.open(audioStream);

        audioClip.start();

        while (!playCompleted) {
            // wait for the playback completes
            try {
                Thread.sleep(1000);
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            }
        }

        audioClip.close();

    } catch (UnsupportedAudioFileException ex) {
        System.out.println("The specified audio file is not supported.");
        ex.printStackTrace();
    } catch (LineUnavailableException ex) {
        System.out.println("Audio line for playing back is unavailable.");
        ex.printStackTrace();
    } catch (IOException ex) {
        System.out.println("Error playing the audio file.");
        ex.printStackTrace();
    }

}

/**
 * Listens to the START and STOP events of the audio line.
 */
@Override
public void update(LineEvent event) {
    LineEvent.Type type = event.getType();

    if (type == LineEvent.Type.START) {
        System.out.println("Playback started.");

    } else if (type == LineEvent.Type.STOP) {
        playCompleted = true;
        System.out.println("Playback completed.");
    }

}

public static void main(String[] args) {
    String audioFilePath = "E:/Test/Audio.wav";
    Sound player = new Sound();
    player.play(audioFilePath);
}

}