StringUtil.java Source code

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Here is the source code for StringUtil.java

Source

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/*
 * JBoss DNA (http://www.jboss.org/dna)
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * See the AUTHORS.txt file in the distribution for a full listing of 
 * individual contributors.
 *
 * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
 * is licensed to you 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.
 *
 * JBoss DNA 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

/**
 * Utilities for string processing and manipulation.
 */
public class StringUtil {

    /**
     * Center the contents of the string. If the supplied string is longer than the desired width, it is truncated to the
     * specified length. If the supplied string is shorter than the desired width, padding characters are added to the beginning
     * and end of the string such that the length is that specified; one additional padding character is prepended if required.
     * All leading and trailing whitespace is removed before centering.
     * 
     * @param str the string to be left justified; if null, an empty string is used
     * @param width the desired width of the string; must be positive
     * @param padWithChar the character to use for padding, if needed
     * @return the left justified string
     * @see #setLength(String, int, char)
     */
    public static String justifyCenter(String str, final int width, char padWithChar) {
        // Trim the leading and trailing whitespace ...
        str = str != null ? str.trim() : "";

        int addChars = width - str.length();
        if (addChars < 0) {
            // truncate
            return str.subSequence(0, width).toString();
        }
        // Write the content ...
        int prependNumber = addChars / 2;
        int appendNumber = prependNumber;
        if ((prependNumber + appendNumber) != addChars) {
            ++prependNumber;
        }

        final StringBuilder sb = new StringBuilder();

        // Prepend the pad character(s) ...
        while (prependNumber > 0) {
            sb.append(padWithChar);
            --prependNumber;
        }

        // Add the actual content
        sb.append(str);

        // Append the pad character(s) ...
        while (appendNumber > 0) {
            sb.append(padWithChar);
            --appendNumber;
        }

        return sb.toString();
    }

}