StringUtil.java Source code

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Here is the source code for StringUtil.java

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/**
 * Copyright (C) 2007 Google Inc.
 *
 * This 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 2.1 of the License, or (at your option) any later version.
    
 * This 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/**
 * String utilities.
 *
 * @author maxr@google.com (Max Ross)
 */
public class StringUtil {

    /**
     * Helper function for null, empty, and whitespace string testing.
     *
     * @return true if s == null or s.equals("") or s contains only whitespace
     *         characters.
     */
    public static boolean isEmptyOrWhitespace(String s) {
        s = makeSafe(s);
        for (int i = 0, n = s.length(); i < n; i++) {
            if (!Character.isWhitespace(s.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * @return true if s == null or s.equals("")
     */
    public static boolean isEmpty(String s) {
        return makeSafe(s).length() == 0;
    }

    /**
     * Helper function for making null strings safe for comparisons, etc.
     *
     * @return (s == null) ? "" : s;
     */
    public static String makeSafe(String s) {
        return (s == null) ? "" : s;
    }

    /**
     * @return the string provided with its first character capitalized
     */
    public static String capitalize(String s) {
        if (s.length() == 0) {
            return s;
        }
        char first = s.charAt(0);
        char capitalized = Character.toUpperCase(first);
        return (first == capitalized) ? s : capitalized + s.substring(1);
    }
}