java - what do u mean by bluetooth chat in android -

private static final int request_connect_device = 1;  private static final int request_enable_bt = 2;   public static final int message_state_change = 1;  public static final int message_device_name = 4;  public static final int message_toast = 5;  public static final string device_name = "device_name";  public static final string toast = "toast";  protected static final string tag = null;  protected static final boolean d = false;  protected static final int message_read = 3;  protected static final int message_write = 2; 

what u mean these above statement because beginer in android

these constants.

final mean value assigned once.

static means variable shared between instances of class.

private, public , protected access modifiers.