Unable to send MIDI file name to Java to playback music

Question

I could play MIDI file where "filename" is a String type with "asd.mid" value. However, I tried to sent AIR's nativeprocess command to Java, it shown "could not read" error. How come?

Java:

private void playMidi() {
    if(isPlaying.equals("0")) {
        try {
            song = MidiSystem.getSequence(new File(filename)); 
            sequencer = MidiSystem.getSequencer();
            sequencer.setSequence(song);
            sequencer.open();
            sequencer.addMetaEventListener(this);
            sequencer.start();
        } catch (InvalidMidiDataException e) {
            System.out.println("Bad midi file: "+ filename);
            System.exit(1);
        } catch (MidiUnavailableException e) {System.out.println("No sequencer available");
            System.exit(1);
        } catch (IOException e) {System.out.println("Could not read: "+ filename);
            System.exit(1);
        }
        displayMidiInfo(filename);
        } else {
        updateTempoFactor(speed);
        }
    }

Answer 1

Is one using a relative path and the other an absolute? Unless both applications are sitting in the same folder, I'd imagine you'd need the filepath rather than just the filename.