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/* 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 org.apache.qpid.messaging.util.failover;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Map;
import org.apache.qpid.messaging.internal.ConnectionInternal;
import org.apache.qpid.messaging.internal.ConnectionString;
import org.apache.qpid.messaging.internal.FailoverStrategy;
public class DefaultFailoverStrategy implements FailoverStrategy
{
ConnectionString[] _reconnectURLs;
/** seconds (give up and report failure after specified time) */
private long _reconnectTimeout = 1000;
/** n (give up and report failure after specified number of attempts) */
private int _reconnectLimit = 1;
/** seconds (initial delay between failed reconnection attempts) */
private long _reconnectIntervalMin = 1000;
/** seconds (maximum delay between failed reconnection attempts) */
private long _reconnectIntervalMax = 1000;
private ConnectionString _currentUrl;
/** reconnection attemps */
private int _attempts = 0;
/** Index for retrieving a URL from _reconnectURLs */
private int _index = 0;
/* quick and dirty impl for experimentation */
public DefaultFailoverStrategy(String url, Map<String,Object> map)
{
map = map == null ? Collections.EMPTY_MAP : map;
_currentUrl = new ConnectionStringImpl(url,map);
// read the map and fill in the above fields.
if (map.containsKey("reconnect_urls"))
{
String[] urls = ((String)map.get("reconnect_urls")).split(",");
_reconnectURLs = new ConnectionString[urls.length];
for(int i=0; i<urls.length; i++)
{
_reconnectURLs[i] = new ConnectionStringImpl(urls[i],map);
}
}
else
{
_reconnectURLs = new ConnectionString[]{_currentUrl};
}
_reconnectLimit = _reconnectURLs.length;
}
@Override
public boolean failoverAllowed()
{
return (_attempts < _reconnectLimit);
}
@Override
public ConnectionString getNextConnectionString()
{
// quick implementation for experimentation, ignoring timeouts, reconnect intervals etc..
// the _index will wrap around like a circular buffer
_attempts++;
if (_index == _reconnectURLs.length)
{
_index = 0;
}
_currentUrl = _reconnectURLs[_index++];
return _currentUrl;
}
@Override
public ConnectionString getCurrentConnectionString()
{
return _currentUrl;
}
@Override
public void connectionAttained(ConnectionInternal conn)
{
_attempts = 0;
}
class ConnectionStringImpl implements ConnectionString
{
private final String _url;
private final Map<String, Object> _options;
public ConnectionStringImpl(String url, Map<String, Object> options)
{
_url = url;
_options = options;
}
public String getUrl()
{
return _url;
}
public Map<String, Object> getOptions()
{
return _options;
}
}
}
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