1 /*
2  * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/util/IdleConnectionHandler.java,v 1.2 2004/05/13 02:40:36 mbecke Exp $
3  * $Revision: 480424 $
4  * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
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      */
IdleConnectionHandler()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      */
add(HttpConnection connection)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      */
remove(HttpConnection connection)86     public void remove(HttpConnection connection) {
87         connectionToAdded.remove(connection);
88     }
89 
90     /**
91      * Removes all connections referenced by this handler.
92      */
removeAll()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      */
closeIdleConnections(long idleTime)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 }
126