Convert to Sentence Case in Android

Question

My app receives a large amount of paragraph length text. Some of it is all in upper case, some all lower and some a mix. I would like to convert it to sentence case i.e. all sentences should start with an uppercase letter. What would be the most efficient way to perform the conversion? - I could not find any sample code or a library to do this.

Answer 1

The code referenced in the links above did not quite work, so I extended it as follows to turn text like:

"this SENTENce is not neat. neither IS this sentence."

into

"This sentence is not neat. Neither is this sentence."

public static String sentenceCaseForText(String text) {

    if (text == null) return "";

    int pos = 0;
    boolean capitalize = true;
    StringBuilder sb = new StringBuilder(text);

    while (pos < sb.length()) {

        if (capitalize && !Character.isWhitespace(sb.charAt(pos))) {

            sb.setCharAt(pos, Character.toUpperCase(sb.charAt(pos)));
        }
        else if (!capitalize && !Character.isWhitespace(sb.charAt(pos))) {

            sb.setCharAt(pos, Character.toLowerCase(sb.charAt(pos)));
        }

        if (sb.charAt(pos) == '.' || (capitalize && Character.isWhitespace(sb.charAt(pos)))) {

            capitalize = true;
        }
        else {

            capitalize = false;
        }

        pos++;
    }

    return sb.toString();
}