Padding and triming strings
/**
* The utillib library.
* More information is available at http://www.jinchess.com/.
* Copyright (C) 2002-2003 Alexander Maryanovsky.
* All rights reserved.
*
* The utillib library is free software; you can redistribute
* it and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* The utillib library is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with utillib library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import java.util.StringTokenizer;
/**
* A utility class which provides many useful text manipulation methods.
*/
public class TextUtilities{
/**
* Pads the beginning of the given String with the given character until it's
* <code>length</code> characters long. If the given String's size is already
* <code>length</code> or larger, the given string is returned as is.
*/
public static String padStart(String s, char c, int length){
if (s.length()>=length)
return s;
StringBuffer buf = new StringBuffer(s);
for (int i=s.length();i<length;i++)
buf.insert(0,c);
return buf.toString();
}
/**
* Pads the end of the given String with the given character until it's
* <code>length</code> characters long. If the given String's size is already
* <code>length</code> or larger, the given string is returned as is.
*/
public static String padEnd(String s, char c, int length){
if (s.length()>=length)
return s;
StringBuffer buf = new StringBuffer(s);
for (int i=s.length();i<length;i++)
buf.append(c);
return buf.toString();
}
/**
* Pads the given String on both sides equally (if possible) with the given
* character until it's <code>length</code> characters long. If the given
* String's size is already <code>length</code> or larger, the given
* string is returned as is.
*/
public static String padSides(String s, char c, int length){
if (s.length()>=length)
return s;
StringBuffer buf = new StringBuffer(s);
for (int i=s.length();i<length-1;i+=2){
buf.insert(0,c);
buf.append(c);
}
if (buf.length()<length)
buf.insert(0,c);
return buf.toString();
}
/**
* Trims the specified string on the right only.
*/
public static String trimRight(String s){
StringBuffer buf = new StringBuffer(s);
int length = buf.length();
while (Character.isWhitespace(buf.charAt(length - 1)))
buf.setLength(--length);
return buf.toString();
}
/**
* Trims the specified string on the left only.
*/
public static String trimLeft(String s){
int i = 0;
while (Character.isWhitespace(s.charAt(i)))
i++;
return s.substring(i);
}
/**
* <P>Returns a substring of the given StringBuffer's string which consists of
* the characters from the beginning of it until the first occurrence of the
* given delimiter string or if the delimiter doesn't occur, until the end
* of the string. The StringBuffer is modified so it no longer contains those
* characters or the delimiter.
* <P>Examples:
* <UL>
* <LI>nextToken(new StringBuffer("abcdefgh"), "de") returns "abc" and
* the StringBuffer is modified to represent the string "fgh".
* <LI>nextToken(new StringBuffer("abcdefgh"), "a") returns an empty string
* and the StringBuffer is modified to represent the string "bcdefgh".
* <LI>nextToken(new StringBuffer("abcdefgh"), "k") returns "abcdefgh" and
* the StringBuffer is modified to represent an empty string.
* </UL>
*/
public static String nextToken(StringBuffer buf, String delimiter){
String bufStr = buf.toString();
int delimIndex = bufStr.indexOf(delimiter);
if (delimIndex==-1){
buf.setLength(0);
return bufStr;
}
String str = bufStr.substring(0,delimIndex);
buf.reverse();
buf.setLength(buf.length()-delimIndex-delimiter.length());
buf.reverse();
return str;
}
/**
* Returns an array of the tokens produced by the specified string with the
* specified delimiter characters.
*/
public static String [] getTokens(String text, String delimiters){
StringTokenizer tokenizer = new StringTokenizer(text, delimiters);
String [] tokens = new String[tokenizer.countTokens()];
for (int i = 0; i < tokens.length; i++)
tokens[i] = tokenizer.nextToken();
return tokens;
}
/**
* Parses the specified list of integers delimited by the specified
* delimiters.
*/
public static int [] parseIntList(String text, String delimiters){
StringTokenizer tokenizer = new StringTokenizer(text, delimiters);
int [] tokens = new int[tokenizer.countTokens()];
for (int i = 0; i < tokens.length; i++)
tokens[i] = Integer.parseInt(tokenizer.nextToken());
return tokens;
}
/**
* Translates the specified resource name into the context of the specified
* class. Basically, this method returns the name of the resource you need to
* use when loading via a classloader, if via the specified class you would
* load it simply with <code>Class.getResource(resourceName)</code>.
*/
public static String translateResource(Class c, String resourceName){
String path = c.getName();
int dotIndex = path.lastIndexOf('.');
if (dotIndex != -1){
path = path.substring(0, dotIndex);
path = path.replace('.', '/') + '/' + resourceName;
}
else
return resourceName;
return path;
}
/**
* Breaks the specified text into lines no longer than the specified length,
* without breaking words. The breaking is done by inserting newlines at
* appropriate locations. Note that if there are words longer than
* <code>maxLength</code>, they will not be broken.
*/
public static String breakIntoLines(String text, int maxLength){
StringBuffer buf = new StringBuffer(text);
text = text + " "; // Fake an extra space at the end to simplify the algorithm
int lastNewline = -1; // The index of the last newline
int lastSpace = -1; // The index of the last space
int curSpace; // The index of the current space
while ((curSpace = text.indexOf(' ', lastSpace + 1)) != -1){
if ((curSpace - lastNewline - 1 > maxLength) && (lastSpace > lastNewline)){
// lastSpace == lastNewline means the current word is longer than maxLength
buf.setCharAt(lastSpace, '\n');
lastNewline = lastSpace;
}
lastSpace = curSpace;
}
return buf.toString();
}
}