Null object reference exception

[Doctor Pizza]

I have this code:

public class MainActivity extends AppCompatActivity {


TextView text;
FingerprintSimilarity fps;
String str ;
Wave w1, w2;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

Wave w1= new Wave("src/musicG/suonoe_1.wav"); // Base Audio file
Wave w2= new Wave("src/musicG/suono.wav"); // Audio file to compare
// Finding Audio Fingerprint Similarity

FingerprintSimilarity fps = w1.getFingerprintSimilarity(w2);
float score = fps.getScore();
float sim = fps.getSimilarity();

TextView text = (TextView) findViewById(R.id.text);
text.setText((int) score);
}
}

but everytime I try to play it it gives me this:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int com.musicg.wave.WaveHeader.getSampleRate()' on a null object reference

Please help me