Difference between logical operators and or Java

<EditText
        android:id="@+id/myEdit" 
	android:layout_height="wrap_content" android:layout_width="fill_parent"
        android:hint="Some text"
	android:singleLine="true"
</EditText>	

// setHint(CharSequence hint) example
(EditText)findViewById(R.id.myEdit).setHint("My text");
// or int resId as method setHint(int resId) 
EditText myEdit = findViewById(R.id.myEdit);
myEdit.setHint(R.string.app_name);

import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;

public class SoundManager
{
  private SoundPool soundPool;
  private int[] sm;
  Context context;

  public SoundManager(Context context) {
    this.context = context;
    soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
    sm = new int[2];
    // fill your sounds
    sm[0] = soundPool.load(context, R.raw.my_sound1, 1);
    sm[1] = soundPool.load(context, R.raw.my_sound2, 1);
  }

  public final void playSound(int sound) {
      AudioManager mgr = (AudioManager)context.getSystemService(
          Context.AUDIO_SERVICE);  
      float streamVolumeCurrent =
          mgr.getStreamVolume(AudioManager.STREAM_MUSIC);
      float streamVolumeMax = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
      float volume = streamVolumeCurrent / streamVolumeMax;
      soundPool.play(sm[sound], volume, volume, 1, 0, 1f);
  }

  public final void cleanUpIfEnd() {
    sm = null;
    context = null;
    soundPool.release();
    soundPool = null;
  }
}

String MYFILE = "my_file";
FileInputStream fis = openFileInput(MYFILE);
	int c; String sText = "";
	while((c=fis.read())!=-1)
	{

		sText += (char)c; // convert int to char
	 }
	fis.close();						

try {
	    BufferedReader in = new BufferedReader(new FileReader("myfile.txt"));
	    StringBuilder strBuilder = new StringBuilder();
	    String str;
	    while ((str = in.readLine()) != null) {
	       strBuilder.append(str);
	    }
	    in.close();
	} catch (IOException e) {
		e.toString();
	}