Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.commons.vfs2.util; import java.text.MessageFormat; import java.util.MissingResourceException; import java.util.ResourceBundle; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; /** * Formats messages. */ public final class Messages { /** * Map from message code to MessageFormat object for the message. */ private static ConcurrentMap<String, MessageFormat> messageMap = new ConcurrentHashMap<String, MessageFormat>(); private static final ResourceBundle RESOURCES = new CombinedResources("org.apache.commons.vfs2.Resources"); private Messages() { } /** * Formats a message. * * @param code The message code. * @return The formatted message. */ public static String getString(final String code) { return getString(code, new Object[0]); } /** * Formats a message. * * @param code * The message code. * @param param * The message parameter. * @return The formatted message. * @deprecated Will be removed in 3.0 in favor of {@link #getString(String, Object[])} When removed, calls to this * method will automatically recompile to {@link #getString(String, Object[])} */ @Deprecated public static String getString(final String code, final Object param) { return getString(code, new Object[] { param }); } /** * Formats a message. * * @param code The message code. * @param params The message parameters. * @return The formatted message. */ public static String getString(final String code, final Object... params) { try { if (code == null) { return null; } final MessageFormat msg = findMessage(code); return msg.format(params); } catch (final MissingResourceException mre) { return "Unknown message with code \"" + code + "\"."; } } /** * Locates a message by its code. */ private static MessageFormat findMessage(final String code) throws MissingResourceException { // Check if the message is cached MessageFormat msg = messageMap.get(code); if (msg != null) { return msg; } final String msgText = RESOURCES.getString(code); msg = new MessageFormat(msgText); messageMap.putIfAbsent(code, msg); return messageMap.get(code); } }