diff options
Diffstat (limited to 'src/main/java/org/apache/commons/lang3/time/FastTimeZone.java')
-rw-r--r-- | src/main/java/org/apache/commons/lang3/time/FastTimeZone.java | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/lang3/time/FastTimeZone.java b/src/main/java/org/apache/commons/lang3/time/FastTimeZone.java new file mode 100644 index 000000000..d111bed41 --- /dev/null +++ b/src/main/java/org/apache/commons/lang3/time/FastTimeZone.java @@ -0,0 +1,95 @@ +/* + * 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() { + } + +} |