001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.oozie.client.rest;
020
021import java.text.ParseException;
022import java.text.SimpleDateFormat;
023import java.util.ArrayList;
024import java.util.Date;
025import java.util.List;
026import java.util.Locale;
027import java.util.TimeZone;
028
029import org.json.simple.JSONArray;
030import org.json.simple.JSONObject;
031
032
033/**
034 * Json utils methods.
035 */
036public class JsonUtils {
037
038    /*
039     * GMT is the most commonly used timezone; we can save on parsing and
040     * creating a TimeZone by creating a GMT TimeZone once
041     */
042    private static TimeZone GMT_TZ = TimeZone.getTimeZone("GMT");
043    /**
044     * Format a Date in RFC822 with the given time zone.
045     *
046     * @param date date to format.
047     * @param timeZoneId the time zone to use
048     * @return RFC822 for the date, <code>null</code> if the date was <code>null</code>.
049     */
050    public static String formatDateRfc822(Date date, String timeZoneId) {
051        if (date != null) {
052            TimeZone tZone = "GMT".equals(timeZoneId) ? GMT_TZ : TimeZone.getTimeZone(timeZoneId);
053            SimpleDateFormat dateFormater = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US);
054            dateFormater.setTimeZone(tZone);
055            return dateFormater.format(date);
056        }
057        return null;
058    }
059    
060    /**
061     * Format a Date in RFC822 GMT.
062     *
063     * @param date date to format.
064     * @return RFC822 GMT for the date, <code>null</code> if the date was <code>null</code>.
065     */
066    public static String formatDateRfc822(Date date) {
067        return formatDateRfc822(date, "GMT");
068    }
069
070    /**
071     * Parse a string in RFC822 GMT format.
072     *
073     * @param str string to parse.
074     * @return parsed date, <code>null</code> if the string was <code>null</code> or in an invalid format.
075     */
076    static Date parseDateRfc822(String str) {
077        if (str != null) {
078            try {
079                SimpleDateFormat dateFormater = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
080                dateFormater.setTimeZone(GMT_TZ);
081                return dateFormater.parse(str);
082            }
083            catch (ParseException ex) {
084                return null;
085            }
086        }
087        return null;
088    }
089
090}