StringUtils.java Source code

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Here is the source code for StringUtils.java

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/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//package jacky.lanlan.song.extension.struts.util;

/**
 * Miscellaneous {@link String} utility methods.
 *
 * <p>Mainly for internal use within the framework; consider
 * <a href="http://jakarta.apache.org/commons/lang/">Jakarta's Commons Lang</a>
 * for a more comprehensive suite of
 * {@link org.apache.commons.lang.StringUtils String utilities}.
 *
 * <p>This class delivers some simple functionality that should really
 * be provided by the core Java <code>String</code> and {@link StringBuffer}
 * classes, such as the ability to {@link #replace} all occurrences of a given
 * substring in a target string. It also provides easy-to-use methods to
 * convert between delimited strings, such as CSV strings, and collections and
 * arrays.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Keith Donald
 * @author Rob Harrop
 * @author Rick Evans
 * @author Jacky.Song
 * @since 16 April 2001
 */
abstract class StringUtils {

    /**
     * Capitalize a <code>String</code>, changing the first letter to
     * upper case as per {@link Character#toUpperCase(char)}.
     * No other letters are changed.
     * @param str the String to capitalize, may be <code>null</code>
     * @return the capitalized String, <code>null</code> if null
     */
    public static String capitalize(String str) {
        return changeFirstCharacterCase(str, true);
    }

    /**
     * Uncapitalize a <code>String</code>, changing the first letter to
     * lower case as per {@link Character#toLowerCase(char)}.
     * No other letters are changed.
     * @param str the String to uncapitalize, may be <code>null</code>
     * @return the uncapitalized String, <code>null</code> if null
     */
    public static String uncapitalize(String str) {
        return changeFirstCharacterCase(str, false);
    }

    private static String changeFirstCharacterCase(String str, boolean capitalize) {
        if (str == null || str.length() == 0) {
            return str;
        }
        StringBuffer buf = new StringBuffer(str.length());
        if (capitalize) {
            buf.append(Character.toUpperCase(str.charAt(0)));
        } else {
            buf.append(Character.toLowerCase(str.charAt(0)));
        }
        buf.append(str.substring(1));
        return buf.toString();
    }

}