    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.math.exception.util;
    018
    019    import java.text.MessageFormat;
    020    import java.util.Locale;
    021
    022    /**
    023     * Class for constructing localized messages.
    024     *
    025     * @since 2.2
    026     * @version $Revision$ $Date$
    027     */
    028    public class MessageFactory {
    029        /**
    030         * Class contains only static methods.
    031         */
    032        private MessageFactory() {}
    033
    034        /**
    035         * Builds a message string by from a pattern and its arguments.
    036         *
    037         * @param locale Locale in which the message should be translated.
    038         * @param pattern Format specifier.
    039         * @param arguments Format arguments.
    040         * @return a localized message string.
    041         */
    042        public static String buildMessage(Locale locale,
    043                                          Localizable pattern,
    044                                          Object ... arguments) {
    045            return buildMessage(locale, null, pattern, arguments);
    046        }
    047
    048        /**
    049         * Builds a message string by from two patterns (specific and general) and
    050         * an argument list.
    051         *
    052         * @param locale Locale in which the message should be translated.
    053         * @param specific Format specifier (may be null).
    054         * @param general Format specifier (may be null).
    055         * @param arguments Format arguments. They will be substituted in
    056         * <em>both</em> the {@code general} and {@code specific} format specifiers.
    057         * @return a localized message string.
    058         */
    059        public static String buildMessage(Locale locale,
    060                                          Localizable specific,
    061                                          Localizable general,
    062                                          Object ... arguments) {
    063            final StringBuilder sb = new StringBuilder();
    064            if (general != null) {
    065                final MessageFormat fmt = new MessageFormat(general.getLocalizedString(locale), locale);
    066                sb.append(fmt.format(arguments));
    067            }
    068            if (specific != null) {
    069                if (general != null) {
    070                    sb.append(": ");
    071                }
    072                final MessageFormat fmt = new MessageFormat(specific.getLocalizedString(locale), locale);
    073                sb.append(fmt.format(arguments));
    074            }
    075
    076            return sb.toString();
    077        }
    078    }