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 {

    /**
     * Right justify the contents of the string, ensuring that the string ends at the last character. If the supplied string is
     * longer than the desired width, the leading characters are removed so that the last character in the supplied string at the
     * last position. If the supplied string is shorter than the desired width, the padding character is inserted one or more
     * times such that the last character in the supplied string appears as the last character in the resulting string and that
     * the length matches that specified.
     * 
     * @param str the string to be right 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 right justified string
     */
    public static String justifyRight(String str, final int width, char padWithChar) {
        assert width > 0;
        // Trim the leading and trailing whitespace ...
        str = str != null ? str.trim() : "";

        final int length = str.length();
        int addChars = width - length;
        if (addChars < 0) {
            // truncate the first characters, keep the last
            return str.subSequence(length - width, length).toString();
        }
        // Prepend the whitespace ...
        final StringBuilder sb = new StringBuilder();
        while (addChars > 0) {
            sb.append(padWithChar);
            --addChars;
        }

        // Write the content ...
        sb.append(str);
        return sb.toString();
    }

}