| /* |
| * 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.catalina.util; |
| |
| import java.text.SimpleDateFormat; |
| import java.util.Date; |
| import java.util.Locale; |
| import java.util.Queue; |
| import java.util.TimeZone; |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| |
| /** |
| * A thread safe wrapper around {@link SimpleDateFormat} that does not make use |
| * of ThreadLocal and - broadly - only creates enough SimpleDateFormat objects |
| * to satisfy the concurrency requirements. |
| */ |
| public class ConcurrentDateFormat { |
| |
| private final String format; |
| private final Locale locale; |
| private final TimeZone timezone; |
| private final Queue<SimpleDateFormat> queue = new ConcurrentLinkedQueue<>(); |
| |
| public static final String RFC1123_DATE = "EEE, dd MMM yyyy HH:mm:ss zzz"; |
| public static final TimeZone GMT = TimeZone.getTimeZone("GMT"); |
| |
| private static final ConcurrentDateFormat FORMAT_RFC1123; |
| |
| static { |
| FORMAT_RFC1123 = new ConcurrentDateFormat(RFC1123_DATE, Locale.US, GMT); |
| } |
| |
| public static String formatRfc1123(Date date) { |
| return FORMAT_RFC1123.format(date); |
| } |
| |
| public ConcurrentDateFormat(String format, Locale locale, |
| TimeZone timezone) { |
| this.format = format; |
| this.locale = locale; |
| this.timezone = timezone; |
| SimpleDateFormat initial = createInstance(); |
| queue.add(initial); |
| } |
| |
| public String format(Date date) { |
| SimpleDateFormat sdf = queue.poll(); |
| if (sdf == null) { |
| sdf = createInstance(); |
| } |
| String result = sdf.format(date); |
| queue.add(sdf); |
| return result; |
| } |
| |
| private SimpleDateFormat createInstance() { |
| SimpleDateFormat sdf = new SimpleDateFormat(format, locale); |
| sdf.setTimeZone(timezone); |
| return sdf; |
| } |
| } |