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+/*
+ * 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.lang3.time;
+
+import java.util.TimeZone;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Faster methods to produce custom time zones.
+ *
+ * @since 3.7
+ */
+public class FastTimeZone {
+
+ private static final Pattern GMT_PATTERN = Pattern.compile("^(?:(?i)GMT)?([+-])?(\\d\\d?)?(:?(\\d\\d?))?$");
+
+ private static final TimeZone GREENWICH = new GmtTimeZone(false, 0, 0);
+
+ /**
+ * Gets the GMT TimeZone.
+ * @return A TimeZone with a raw offset of zero.
+ */
+ public static TimeZone getGmtTimeZone() {
+ return GREENWICH;
+ }
+
+ /**
+ * Gets a TimeZone with GMT offsets. A GMT offset must be either 'Z', or 'UTC', or match
+ * <em>(GMT)? hh?(:?mm?)?</em>, where h and m are digits representing hours and minutes.
+ *
+ * @param pattern The GMT offset
+ * @return A TimeZone with offset from GMT or null, if pattern does not match.
+ */
+ public static TimeZone getGmtTimeZone(final String pattern) {
+ if ("Z".equals(pattern) || "UTC".equals(pattern)) {
+ return GREENWICH;
+ }
+
+ final Matcher m = GMT_PATTERN.matcher(pattern);
+ if (m.matches()) {
+ final int hours = parseInt(m.group(2));
+ final int minutes = parseInt(m.group(4));
+ if (hours == 0 && minutes == 0) {
+ return GREENWICH;
+ }
+ return new GmtTimeZone(parseSign(m.group(1)), hours, minutes);
+ }
+ return null;
+ }
+
+ /**
+ * Gets a TimeZone, looking first for GMT custom ids, then falling back to Olson ids.
+ * A GMT custom id can be 'Z', or 'UTC', or has an optional prefix of GMT,
+ * followed by sign, hours digit(s), optional colon(':'), and optional minutes digits.
+ * i.e. <em>[GMT] (+|-) Hours [[:] Minutes]</em>
+ *
+ * @param id A GMT custom id (or Olson id
+ * @return A time zone
+ */
+ public static TimeZone getTimeZone(final String id) {
+ final TimeZone tz = getGmtTimeZone(id);
+ if (tz != null) {
+ return tz;
+ }
+ return TimeZone.getTimeZone(id);
+ }
+
+ private static int parseInt(final String group) {
+ return group != null ? Integer.parseInt(group) : 0;
+ }
+
+ private static boolean parseSign(final String group) {
+ return group != null && group.charAt(0) == '-';
+ }
+
+ // do not instantiate
+ private FastTimeZone() {
+ }
+
+}