无法将通过蓝牙接收的字符串与普通字符串进行比较

Question

I have a connection between Arduino and Android phone.

This is the string that I'm receiving: always the string 555 , I know because I tested it:

    final String data = new String(encodedBytes, "US-ASCII");
    String toCompare = data;

But this will always print false :

txtArduino.setText(String.valueOf(toCompare.equals("555")));

I think that the format is different or something like that, because I know for sure that I'm receiving 555 .

Answer 1

53 53 53 13 in ASCII is 5 5 5 ␍

new String converts that to Unicode/UTF-16, which as a literal in Java would be "555\\r" or "555\ ". So, you should compare to that.

final String data = new String(encodedBytes, "US-ASCII");
String toCompare = data;

txtArduino.setText(String.valueOf(toCompare.equals("555\r")));

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Depending on your Bluetooth library, you might have to consider that you are receiving a stream of bytes and that each read gives you all available bytes. It would then be up to you to split the stream into messages. This could be the purpose of the ␍.

Answer 2

Your input string includes the newline at the end. Trim it.