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1   /*
2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/oac.hc3x/trunk/src/java/org/apache/commons/httpclient/util/IdleConnectionHandler.java $
3    * $Revision: 1425331 $
4    * $Date: 2012-12-22 19:29:41 +0100 (Sat, 22 Dec 2012) $
5    *
6    * ====================================================================
7    *
8    *  Licensed to the Apache Software Foundation (ASF) under one or more
9    *  contributor license agreements.  See the NOTICE file distributed with
10   *  this work for additional information regarding copyright ownership.
11   *  The ASF licenses this file to You under the Apache License, Version 2.0
12   *  (the "License"); you may not use this file except in compliance with
13   *  the License.  You may obtain a copy of the License at
14   *
15   *      http://www.apache.org/licenses/LICENSE-2.0
16   *
17   *  Unless required by applicable law or agreed to in writing, software
18   *  distributed under the License is distributed on an "AS IS" BASIS,
19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20   *  See the License for the specific language governing permissions and
21   *  limitations under the License.
22   * ====================================================================
23   *
24   * This software consists of voluntary contributions made by many
25   * individuals on behalf of the Apache Software Foundation.  For more
26   * information on the Apache Software Foundation, please see
27   * <http://www.apache.org/>.
28   *
29   */
30  package org.apache.commons.httpclient.util;
31  
32  import java.util.HashMap;
33  import java.util.Iterator;
34  import java.util.Map;
35  
36  import org.apache.commons.httpclient.HttpConnection;
37  import org.apache.commons.logging.Log;
38  import org.apache.commons.logging.LogFactory;
39  
40  /***
41   * A helper class for connection managers to track idle connections.
42   * 
43   * <p>This class is not synchronized.</p>
44   * 
45   * @see org.apache.commons.httpclient.HttpConnectionManager#closeIdleConnections(long)
46   * 
47   * @since 3.0
48   */
49  public class IdleConnectionHandler {
50      
51      private static final Log LOG = LogFactory.getLog(IdleConnectionHandler.class);
52      
53      /*** Holds connections and the time they were added. */
54      private Map connectionToAdded = new HashMap();
55      
56      /***
57       * 
58       */
59      public IdleConnectionHandler() {
60          super();
61      }
62      
63      /***
64       * Registers the given connection with this handler.  The connection will be held until 
65       * {@link #remove(HttpConnection)} or {@link #closeIdleConnections(long)} is called.
66       * 
67       * @param connection the connection to add
68       * 
69       * @see #remove(HttpConnection)
70       */
71      public void add(HttpConnection connection) {
72          
73          Long timeAdded = new Long(System.currentTimeMillis());
74          
75          if (LOG.isDebugEnabled()) {
76              LOG.debug("Adding connection at: " + timeAdded);
77          }
78          
79          connectionToAdded.put(connection, timeAdded);
80      }
81      
82      /***
83       * Removes the given connection from the list of connections to be closed when idle.
84       * @param connection
85       */
86      public void remove(HttpConnection connection) {
87          connectionToAdded.remove(connection);
88      }
89  
90      /***
91       * Removes all connections referenced by this handler.
92       */
93      public void removeAll() {
94          this.connectionToAdded.clear();
95      }
96      
97      /***
98       * Closes connections that have been idle for at least the given amount of time.
99       * 
100      * @param idleTime the minimum idle time, in milliseconds, for connections to be closed
101      */
102     public void closeIdleConnections(long idleTime) {
103         
104         // the latest time for which connections will be closed
105         long idleTimeout = System.currentTimeMillis() - idleTime;
106 
107         if (LOG.isDebugEnabled()) {
108             LOG.debug("Checking for connections, idleTimeout: "  + idleTimeout);
109         }
110         
111         Iterator connectionIter = connectionToAdded.keySet().iterator();
112         
113         while (connectionIter.hasNext()) {
114             HttpConnection conn = (HttpConnection) connectionIter.next();
115             Long connectionTime = (Long) connectionToAdded.get(conn);
116             if (connectionTime.longValue() <= idleTimeout) {
117                 if (LOG.isDebugEnabled()) {
118                     LOG.debug("Closing connection, connection time: "  + connectionTime);
119                 }
120                 connectionIter.remove();
121                 conn.close();
122             }
123         }
124     }
125 }