public class ColumnPrintStringBuffer {
        //we cannot extend from Stringbuffer (it's final), so we aggregate it
        private StringBuffer sb;
        private int columnLength;
        private int currentLineLength = 0;
        public ColumnPrintStringBuffer(int columnLength) {
            sb = new StringBuffer();
            this.columnLength = columnLength;
        }

        public ColumnPrintStringBuffer append(String str) {
            StringTokenizer lineTokenizer = new StringTokenizer(str, "\n\r\f");
            while (lineTokenizer.hasMoreTokens()) {
                appendLine(lineTokenizer.nextToken());
                if(lineTokenizer.hasMoreTokens())
                    sb.append("\n");
            }
            return this;
        }

        protected void appendLine(String line){
            StringTokenizer wordTokenizer = new StringTokenizer(line, " \t");
            if(wordTokenizer.hasMoreTokens()) {
                String current = wordTokenizer.nextToken();
                String lookAhead = null;
                while(wordTokenizer.hasMoreTokens()) {
                    lookAhead = wordTokenizer.nextToken();
                    appendWord(current, lookAhead);
                    current = lookAhead;
                    lookAhead = null;
                }
                appendWord(current, lookAhead);
            }
        }

        protected void appendWord(String word, String lookAheadWord) {
            if(currentLineLength + word.length() <= columnLength){
                currentLineLength += word.length();
                sb.append(word);
                if(lookAheadWord != null && currentLineLength+ 1 + lookAheadWord.length() <= columnLength) {
                    currentLineLength++;
                    sb.append(" ");
                } else {
                    currentLineLength = 0;
                    if(lookAheadWord != null)
                        sb.append("\n");
                }
            } else {
                currentLineLength = word.length();
                sb.append("\n").append(word);
            }
        }

        @Override
        public String toString() {
            return sb.toString();
        }

	public static void main (String[] args) {
	    String s1 = "The quick brown fox jumped over the lazy dog.\n";
            String s2 = "The quick\nbrown fox jumped over\nthe lazy dog.";
            ColumnPrintStringBuffer cpsb = new ColumnPrintStringBuffer(10);
            cpsb.append(s1);
            cpsb.append(s2);
            System.out.println(cpsb.toString());
}