/
OnDemandBeanInstance.java
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/
OnDemandBeanInstance.java
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/*
* JBoss, Home of Professional Open Source.
* Copyright 2011, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.weld.injection;
import java.io.Serializable;
import org.jboss.weld.bean.proxy.AbstractBeanInstance;
/**
* Create instance on demand / lazy.
*
* @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
*/
class OnDemandBeanInstance extends AbstractBeanInstance implements Serializable {
private InstanceProvider provider;
private volatile Object instance;
public OnDemandBeanInstance(InstanceProvider provider) {
this.provider = provider;
}
public Object getInstance() {
if (instance == null) {
synchronized (this) {
if (instance == null) {
instance = provider.provideInstance();
provider = null;
}
}
}
return instance;
}
public Class<?> getInstanceType() {
return getInstance().getClass();
}
static interface InstanceProvider extends Serializable {
Object provideInstance();
}
}