public static String getDeviceSerial() {  String serial = "unknown";  try {   Class clazz = Class.forName("android.os.Build");   Class paraTypes = Class.forName("java.lang.String");   Method method = clazz.getDeclaredMethod("getString", paraTypes);   if (!method.isAccessible()) {    method.setAccessible(true);   }   serial = (String)method.invoke(new Build(), "ro.serialno");  } catch (ClassNotFoundException e) {   e.printStackTrace();  } catch (NoSuchMethodException e) {   e.printStackTrace();  } catch (InvocationTargetException e) {   e.printStackTrace();  } catch (IllegalAccessException e) {   e.printStackTrace();  }  return serial;}