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1   /****************************************************************
2    * Licensed to the Apache Software Foundation (ASF) under one   *
3    * or more contributor license agreements.  See the NOTICE file *
4    * distributed with this work for additional information        *
5    * regarding copyright ownership.  The ASF licenses this file   *
6    * to you under the Apache License, Version 2.0 (the            *
7    * "License"); you may not use this file except in compliance   *
8    * with the License.  You may obtain a copy of the License at   *
9    *                                                              *
10   *   http://www.apache.org/licenses/LICENSE-2.0                 *
11   *                                                              *
12   * Unless required by applicable law or agreed to in writing,   *
13   * software distributed under the License is distributed on an  *
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
15   * KIND, either express or implied.  See the License for the    *
16   * specific language governing permissions and limitations      *
17   * under the License.                                           *
18   ****************************************************************/
19  
20  
21  package org.apache.james.util;
22  
23  import java.util.Collections;
24  import java.util.HashMap;
25  import java.util.Iterator;
26  import java.util.Map;
27  
28  /**
29   * Helper class which is used to store ipAddresses and timestamps for pop before
30   * smtp support.
31   */
32  public class POP3BeforeSMTPHelper {
33  
34      private POP3BeforeSMTPHelper() {
35      }
36  
37      /**
38       * The map in which the ipAddresses and timestamp stored
39       */
40      public static Map ipMap = Collections.synchronizedMap(new HashMap());
41  
42      /**
43       * Default expire time in ms (1 hour)
44       */
45      public static final long EXPIRE_TIME = 216000000;
46  
47      /**
48       * Return true if the ip is authorized to relay
49       * 
50       * @param ipAddress
51       *            The ipAddress
52       * @return true if authorized. Else false
53       */
54      public static boolean isAuthorized(String ipAddress) {
55          return ipMap.containsKey(ipAddress);
56      }
57  
58      /**
59       * Add the ipAddress to the authorized ipAddresses
60       * 
61       * @param ipAddress
62       *            The ipAddress
63       */
64      public static void addIPAddress(String ipAddress) {
65          ipMap.put(ipAddress, Long.toString(System.currentTimeMillis()));
66      }
67  
68      /**
69       * @see #removeExpiredIP(long)
70       */
71      public static void removeExpiredIP() {
72          removeExpiredIP(EXPIRE_TIME);
73      }
74  
75      /**
76       * Remove all ipAddress from the authorized map which are older then the
77       * given time
78       * 
79       * @param clearTime
80       *            The time in milliseconds after which an ipAddress should be
81       *            handled as expired
82       */
83      public static void removeExpiredIP(long clearTime) {
84          synchronized (ipMap) {
85              Iterator storedIP = ipMap.keySet().iterator();
86              long currTime = System.currentTimeMillis();
87  
88              while (storedIP.hasNext()) {
89                  String key = storedIP.next().toString();
90                  long storedTime = Long.parseLong((String) ipMap.get(key));
91  
92                  // remove the ip from the map when it is expired
93                  if ((currTime - clearTime) > storedTime) {
94                      // remove the entry from the iterator first to get sure that we not get 
95                      // a ConcurrentModificationException
96                      storedIP.remove();
97  
98                      ipMap.remove(key);
99                  }
100             }
101         }
102     }
103 
104     /**
105      * Remove all ipAddresses from the authorized map
106      */
107     public static void clearIP() {
108         ipMap.clear();
109     }
110 }