regular expression to remove all non-printable characters

Tar.Aldarion

I wish to remove all non-printable ascii characters from a string while retaining invisible ones. I thought this would work because whitespace, \n \r \b are invisible characters but not non-printable? Basically I am getting a byte array with � characters in it (\uFFFd) and I don't want them to be in it. So i am trying to convert it to a string, remove the � characters before using it as a byte array again.

With the code below they are removed but so are any occurences of \r \n and \b. What would be the correct regex to retain these also? Or is there a better way that what I am doing?

public void write(byte[] bytes, int offset, int count) 
{

    try {
        String str = new String(bytes, "UTF-8");
        str2 = str.replaceAll("[^\\p{Print}\t\n]", "");
        GraphicsTerminalActivity.sendOverSerial(str2.getBytes("UTF-8"));

    } catch (UnsupportedEncodingException e) {

        e.printStackTrace();
    }

     return;
    }

}

Do I have to add some clause for ascii control characters?

PrzemoF

Try:

replaceAll("\\p{C}", "?");

http://stackoverflow.com/questions/6198986/how-can-i-replace-non-printable-unicode-characters-in-java

Tar.Aldarion

Thanks, I tried that earlier and I get the exact same functionality as I do at the moment. Although I was trying replaceAll("\\p{C}", ""); due to ? listing all options in the terminal.

Tar.Aldarion

I tried [^\\x00-\\x7F] which is the range of ascii characters....but then the � symbols still get through, weird.