为什么openFd（filename）不能与String一起使用？

Question

private void startSound(String filename) throws IOException{
    AssetFileDescriptor afd = getAssets().openFd(filename);
    MediaPlayer player = new MediaPlayer();
    player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
    player.prepare();
    player.start();
}

@Override
public void onClick(View v) {
    switch(v.getId()) {
case R.id.addForLearning:

        break;
    case R.id.music:

        String words = mainDataTextView.getText().toString();

        String con = "voice/"+words+".mp3";

        try {
            startSound(con);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        break;

Why S tring in openFd(filename) don't work? I got FileNotFoundException . If I type openFd("voice/song.mp3") all working, but it don't right for me.

Answer 1

I would wager quite a bit that the string that you get from your textview isn't trimmed of whitespaces.

Try

String words = mainDataTextView.getText().toString();
String trimmedWords = words.trim();
String con = "voice/"+trimmedWords+".mp3";

Also, if this is not correct, could you print what words contains?