Mega Code Archive
Word Wrap
<![CDATA[
/**
* $Revision: 10205 $
* $Date: 2008-04-11 15:48:27 -0700 (Fri, 11 Apr 2008) $
*
* Copyright (C) 2004-2008 Jive Software. All rights reserved.
*
* This software is published under the terms of the GNU Public License (GPL),
* a copy of which is included in this distribution, or a commercial license
* agreement with Jive.
*/
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.BreakIterator;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
/**
* Utility class to peform common String manipulation algorithms.
*/
public class StringUtils {
// Constants used by escapeHTMLTags
private static final char[] QUOTE_ENCODE = """.toCharArray();
private static final char[] AMP_ENCODE = "&".toCharArray();
private static final char[] LT_ENCODE = "<".toCharArray();
private static final char[] GT_ENCODE = ">".toCharArray();
private StringUtils() {
// Not instantiable.
}
/**
* Reformats a string where lines that are longer than <tt>width</tt>
* are split apart at the earliest wordbreak or at maxLength, whichever is
* sooner. If the width specified is less than 5 or greater than the input
* Strings length the string will be returned as is.
* <p/>
* Please note that this method can be lossy - trailing spaces on wrapped
* lines may be trimmed.
*
* @param input the String to reformat.
* @param width the maximum length of any one line.
* @return a new String with reformatted as needed.
*/
public static String wordWrap(String input, int width, Locale locale) {
// protect ourselves
if (input == null) {
return "";
}
else if (width < 5) {
return input;
}
else if (width >= input.length()) {
return input;
}
StringBuilder buf = new StringBuilder(input);
boolean endOfLine = false;
int lineStart = 0;
for (int i = 0; i < buf.length(); i++) {
if (buf.charAt(i) == '\n') {
lineStart = i + 1;
endOfLine = true;
}
// handle splitting at width character
if (i > lineStart + width - 1) {
if (!endOfLine) {
int limit = i - lineStart - 1;
BreakIterator breaks = BreakIterator.getLineInstance(locale);
breaks.setText(buf.substring(lineStart, i));
int end = breaks.last();
// if the last character in the search string isn't a space,
// we can't split on it (looks bad). Search for a previous
// break character
if (end == limit + 1) {
if (!Character.isWhitespace(buf.charAt(lineStart + end))) {
end = breaks.preceding(end - 1);
}
}
// if the last character is a space, replace it with a \n
if (end != BreakIterator.DONE && end == limit + 1) {
buf.replace(lineStart + end, lineStart + end + 1, "\n");
lineStart = lineStart + end;
}
// otherwise, just insert a \n
else if (end != BreakIterator.DONE && end != 0) {
buf.insert(lineStart + end, '\n');
lineStart = lineStart + end + 1;
}
else {
buf.insert(i, '\n');
lineStart = i + 1;
}
}
else {
buf.insert(i, '\n');
lineStart = i + 1;
endOfLine = false;
}
}
}
return buf.toString();
}
}
]]>