Using javax.sound.sampled.Clip to play, loop, and stop multiple sounds in a game. Unexpected Errors

I was able to get the code working and now have a better understanding of Clips. The page that helped me the most was http://www3.ntu.edu.sg/home/ehchua/programming/java/J8c_PlayingSound.html it breaks everything down and helped me see where I made mistakes. Here is my final working code. As before if you see any horrible errors or over sights in logic or style let me know.

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;

/**
 * Handles playing, stoping, and looping of sounds for the game.
 * @author Tyler Thomas
 *
 */
public class Sound {
    private Clip clip;
    public Sound(String fileName) {
        // specify the sound to play
        // (assuming the sound can be played by the audio system)
        // from a wave File
        try {
            File file = new File(fileName);
            if (file.exists()) {
                AudioInputStream sound = AudioSystem.getAudioInputStream(file);
             // load the sound into memory (a Clip)
                clip = AudioSystem.getClip();
                clip.open(sound);
            }
            else {
                throw new RuntimeException("Sound: file not found: " + fileName);
            }
        }
        catch (MalformedURLException e) {
            e.printStackTrace();
            throw new RuntimeException("Sound: Malformed URL: " + e);
        }
        catch (UnsupportedAudioFileException e) {
            e.printStackTrace();
            throw new RuntimeException("Sound: Unsupported Audio File: " + e);
        }
        catch (IOException e) {
            e.printStackTrace();
            throw new RuntimeException("Sound: Input/Output Error: " + e);
        }
        catch (LineUnavailableException e) {
            e.printStackTrace();
            throw new RuntimeException("Sound: Line Unavailable Exception Error: " + e);
        }

    // play, stop, loop the sound clip
    }
    public void play(){
        clip.setFramePosition(0);  // Must always rewind!
        clip.start();
    }
    public void loop(){
        clip.loop(Clip.LOOP_CONTINUOUSLY);
    }
    public void stop(){
            clip.stop();
        }
    }

I found a useful technique to stop sound. You can copy these two classes down and test it out for yourself. Nevertheless, the clip.stop() method is more of a pause method. It stops the sound from playing, yes, but it does not clear the sound from the line. As a result, the sound is still queued to play and no new sound can be played. So using the clip.close() method will clear out this queued data and allow a new sound to be played or another action to take place. Also note in the following code a sound file was placed in the project folder called "predator.wav" this sound can be any type of sound you want to use instead of the sound I chose, but be sure it is a .wav format and the sound must be in the top-most tier of the project folder.

/*
 * File: KeyMap.java
 * Author: Andrew Peturis Chaselyn Langley; UAB EE Students
 * Assignment:  SoundBox - EE333 Fall 2015
 * Vers: 1.0.0 10/20/2015 agp - initial coding
 *
 * Credits: Dr. Green, UAB EE Engineering Professor
 */

import java.io.File;
import java.io.IOException;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;

public class KeyMap {

    private char keyCode;
    private String song;
    private Clip clip;

    // Don't allow default constructor
    private KeyMap() {
    }

    public KeyMap(char keyCode, String song) throws LineUnavailableException {
        this.keyCode = keyCode;
        this.song = song;

        // Create an audiostream from the inputstream
        clip = AudioSystem.getClip();
    }

    public boolean match(char key) {
        return key == keyCode;
    }

    // Play a sound using javax.sound and Clip interface
    public String play() {
        try {
            // Open a sound file stored in the project folder
            clip.open(AudioSystem.getAudioInputStream(new File(song + ".wav")));

            // Play the audio clip with the audioplayer class
            clip.start();

            // Create a sleep time of 2 seconds to prevent any action from occuring for the first
            // 2 seconds of the sound playing
            Thread.sleep(2000);

        } catch (LineUnavailableException | UnsupportedAudioFileException | IOException | InterruptedException e) {
            System.out.println("Things did not go well");
            System.exit(-1);
        }
        return song;
    }

    // Stop a sound from playing and clear out the line to play another sound if need be.
    public void stop() {
        // clip.stop() will only pause the sound and still leave the sound in the line
        // waiting to be continued. It does not actually clear the line so a new action could be performed.
        clip.stop();

        // clip.close(); will clear out the line and allow a new sound to play. clip.flush() was not 
        // used because it can only flush out a line of data already performed.
        clip.close();
    }
}

/*
 * File: SoundBox.java
 * Author: Andrew Peturis, Chaselyn Langley; UAB EE Students
 * Assignment:  GUI SoundBox - EE333 Fall 2015
 * Vers: 1.0.0 09/08/2015 agp - initial coding
 */

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Scanner;
import javax.sound.sampled.LineUnavailableException;

/**
 *
 * @author Andrew Peturis, Chaselyn Langley
 *
 */
public class SoundBox {

    static Scanner scanner = new Scanner(System.in);   //Scanner object to read user input
    InputStream input;

    /**
     * @param args the command line arguments
     * @throws java.io.IOException
     */
    public static void main(String[] args) throws IOException, LineUnavailableException {

        String line;
        Character firstChar;
        String predator = "predator";
        String explosion = "explosion";

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        KeyMap[] keyedSongs = {
            new KeyMap('a', predator),};

        while (true) {
            line = br.readLine();
            firstChar = line.charAt(0);

            for (int i = 0; i < keyedSongs.length; i++) {
                if (keyedSongs[i].match(firstChar)) {

                    // Notice now by running the code, after the first second of sleep time the sound can
                    // and another sound can be played in its place
                    keyedSongs[i].stop();
                    System.out.println("Played the sound: " + keyedSongs[i].play());
                    break;
                }
            }

            if (firstChar == 'q') {
                break;
            }
        }
    }
}