Import code from internal repository to git

java/com/google/domain/registry/tools/params/DateTimeParameter.java

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+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed 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 com.google.domain.registry.tools.params;
+
+import static org.joda.time.DateTimeZone.UTC;
+
+import com.google.common.primitives.Longs;
+
+import org.joda.time.DateTime;
+import org.joda.time.format.DateTimeFormatter;
+import org.joda.time.format.DateTimeFormatterBuilder;
+import org.joda.time.format.DateTimeParser;
+import org.joda.time.format.ISODateTimeFormat;
+
+/** {@linkplain DateTime} CLI parameter converter/validator. Can be ISO or millis from epoch. */
+public final class DateTimeParameter extends ParameterConverterValidator<DateTime> {
+
+  public DateTimeParameter() {
+    super("not an ISO-8601 timestamp (or millis from epoch)");
+  }
+
+  /**
+   * Parser for DateTimes that permits only a restricted subset of ISO 8601 datetime syntax.
+   * The supported format is "YYYY-MM-DD'T'HH:MM:SS[.SSS]ZZ", i.e. there must be a complete date
+   * and at least hours, minutes, seconds, and time zone; milliseconds are optional.
+   * <p>
+   * We use this instead of the default {@link ISODateTimeFormat#dateTimeParser()} because that
+   * parser is very flexible and accepts date times with missing dates, missing dates, and various
+   * other unspecified fields that can lead to confusion and ambiguity.
+   */
+  private static final DateTimeFormatter STRICT_DATE_TIME_PARSER = new DateTimeFormatterBuilder()
+      .append(null, new DateTimeParser[] {
+          // The formatter will try the following parsers in order until one succeeds.
+          ISODateTimeFormat.dateTime().getParser(),
+          ISODateTimeFormat.dateTimeNoMillis().getParser()})
+      .toFormatter();
+
+  @Override
+  public DateTime convert(String value) {
+    Long millis = Longs.tryParse(value);
+    if (millis != null) {
+      return new DateTime(millis.longValue(), UTC);
+    }
+    return DateTime.parse(value, STRICT_DATE_TIME_PARSER).withZone(UTC);
+  }
+}