Text split after a specified length but dont break words using grails

Question

I have a long string that I need to parse into an array of strings that do not exceed 50 characters in length. The tricky part of this for me is making sure that the regex finds the last whitespace before 50 characters to make a clean break between strings since I don't want words cut off.

public List<String> splitInfoText(String msg) { 
     int MAX_WIDTH = 50; 
     def line = [] String[] words; 
     msg = msg.trim(); 
     words = msg.split(" "); 
     StringBuffer s = new StringBuffer(); 
     words.each {
        word -> s.append(word + " "); 
        if (s.length() > MAX_WIDTH) { 
          s.replace(s.length() - word.length()-1, s.length(), " "); 
          line << s.toString().trim();
          s = new StringBuffer(word + " "); 
        } 
     } 
     if (s.length() > 0) 
        line << s.toString().trim();
     return line; 
}

Answer 1

Try this:

List<String> matchList = new ArrayList<String>();
Pattern regex = Pattern.compile(".{1,50}(?:\\s|$)", Pattern.DOTALL);
Matcher regexMatcher = regex.matcher(subjectString);
while (regexMatcher.find()) {
    matchList.add(regexMatcher.group());
}

Answer 2

I believe a Groovier version of Tim's answer is:

List matchList = ( subjectString =~ /(?s)(.{1,50})(?:\s|$)/ ).collect { it[ 1 ] }