org.apache.openjpa.conf.BrokerValue Maven / Gradle / Ivy
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* distributed with this work for additional information
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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*/
package org.apache.openjpa.conf;
import org.apache.openjpa.lib.conf.PluginValue;
import org.apache.openjpa.lib.conf.Configuration;
import org.apache.openjpa.kernel.BrokerImpl;
import org.apache.openjpa.kernel.FinalizingBrokerImpl;
import org.apache.openjpa.util.InternalException;
/**
* Custom {@link PluginValue} that can efficiently create {@link BrokerImpl}
* instances.
*
* @since 0.9.7
*/
public class BrokerValue
extends PluginValue {
public static final String KEY = "BrokerImpl";
public static final String NON_FINALIZING_ALIAS = "non-finalizing";
public static final String DEFAULT_ALIAS = "default";
private BrokerImpl _templateBroker;
public BrokerValue() {
super(KEY, false);
String[] aliases = new String[] {
DEFAULT_ALIAS, FinalizingBrokerImpl.class.getName(),
NON_FINALIZING_ALIAS, BrokerImpl.class.getName(),
};
setAliases(aliases);
setDefault(aliases[0]);
setString(aliases[0]);
}
public Object newInstance(String clsName, Class type, Configuration conf,
boolean fatal) {
getTemplateBroker(clsName, type, conf, fatal);
try {
return _templateBroker.clone();
} catch (CloneNotSupportedException e) {
throw new InternalException(e);
}
}
public Class getTemplateBrokerType(Configuration c) {
return getTemplateBroker(getClassName(), BrokerImpl.class, c, true)
.getClass();
}
private BrokerImpl getTemplateBroker(String clsName, Class type,
Configuration conf, boolean fatal) {
if (clsName == null || !clsName.equals(getClassName()))
throw new IllegalArgumentException("clsName != configured value '"
+ getClassName() + "'");
// This is not synchronized. If there are concurrent invocations
// while _templateBroker is null, we'll just end up with extra
// template brokers, which will get safely garbage collected.
if (_templateBroker == null)
_templateBroker = (BrokerImpl) super.newInstance(clsName, type,
conf, fatal);
return _templateBroker;
}
}