Review

class StringUtils {
    /**
     * <p>Returns either the passed in String,
     * or if the String is <code>null</code>, an empty String ("").</p>
     *
     * <pre>
     * StringUtils.defaultString(null)  = ""
     * StringUtils.defaultString("")    = ""
     * StringUtils.defaultString("bat") = "bat"
     * </pre>
     *
     * @see ObjectUtils#toString(Object)
     * @see String#valueOf(Object)
     * @param str  the String to check, may be null
     * @return the passed in String, or the empty String if it
     *  was <code>null</code>
     */
    public static String defaultString(String str) {
        return str == null ? EMPTY : str;
    }

}