content: /*
   * 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 com.aliyuncs.fc.utils;
  
  import com.google.gson.Gson;
  
  import java.security.MessageDigest;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.Locale;
  import java.util.SimpleTimeZone;
  import java.util.UUID;
  
  public class ParameterHelper {
  
      private final static String TIME_ZONE = "GMT";
      private final static String FORMAT_ISO8601 = "yyyy-MM-dd'T'HH:mm:ss'Z'";
      private final static String FORMAT_RFC2616 = "EEE, dd MMM yyyy HH:mm:ss zzz";
  
      public ParameterHelper() {
      }
  
      public static String getUniqueNonce() {
          UUID uuid = UUID.randomUUID();
          return uuid.toString();
      }
  
      public static String getISO8601Time(Date date) {
          Date nowDate = date;
          if (null == date) {
              nowDate = new Date();
          }
          SimpleDateFormat df = new SimpleDateFormat(FORMAT_ISO8601);
          df.setTimeZone(new SimpleTimeZone(0, TIME_ZONE));
  
          return df.format(nowDate);
      }
  
      public static String getRFC2616Date(Date date) {
          Date nowDate = date;
          if (null == date) {
              nowDate = new Date();
          }
          SimpleDateFormat df = new SimpleDateFormat(FORMAT_RFC2616, Locale.ENGLISH);
          df.setTimeZone(new SimpleTimeZone(0, TIME_ZONE));
          return df.format(nowDate);
      }
  
      public static Date parse(String strDate) throws ParseException {
          if (null == strDate || "".equals(strDate)) {
              return null;
          }
          try {
              return parseISO8601(strDate);
          } catch (ParseException exp) {
              return parseRFC2616(strDate);
          }
      }
  
      public static Date parseISO8601(String strDate) throws ParseException {
          if (null == strDate || "".equals(strDate)) {
              return null;
          }
          SimpleDateFormat df = new SimpleDateFormat(FORMAT_ISO8601);
          df.setTimeZone(new SimpleTimeZone(0, TIME_ZONE));
          return df.parse(strDate);
      }
  
      public static Date parseRFC2616(String strDate) throws ParseException {
          if (null == strDate || "".equals(strDate) || strDate.length() != FORMAT_RFC2616.length()) {
              return null;
          }
          SimpleDateFormat df = new SimpleDateFormat(FORMAT_RFC2616, Locale.ENGLISH);
          df.setTimeZone(new SimpleTimeZone(0, TIME_ZONE));
          return df.parse(strDate);
      }
  
      public static String md5Sum(byte[] buff) {
          try {
              MessageDigest md = MessageDigest.getInstance("MD5");
              byte[] messageDigest = md.digest(buff);
              return Base64Helper.encode(messageDigest);
          } catch (Exception e) {
          }
          return null;
      }
  
      public static String ObjectToJson(Object o) {
          Gson gson = new Gson();
          String jsonStr = gson.toJson(o);
          return jsonStr;
      }
  }