svn-gvsig-desktop / trunk / org.gvsig.desktop / org.gvsig.desktop.compat.cdc / org.gvsig.fmap.dal / org.gvsig.fmap.dal.spi / src / main / java / org / gvsig / fmap / dal / resource / spi / AbstractResource.java @ 44376
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/**
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* gvSIG. Desktop Geographic Information System.
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*
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* Copyright (C) 2007-2013 gvSIG Association.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 3
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*
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* For any additional information, do not hesitate to contact us
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* at info AT gvsig.com, or visit our website www.gvsig.com.
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*/
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package org.gvsig.fmap.dal.resource.spi; |
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import java.lang.ref.WeakReference; |
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import java.util.ArrayList; |
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import java.util.Iterator; |
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import java.util.List; |
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import org.gvsig.fmap.dal.exception.CopyParametersException; |
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import org.gvsig.fmap.dal.exception.InitializeException; |
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import org.gvsig.fmap.dal.resource.Resource; |
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import org.gvsig.fmap.dal.resource.ResourceAction; |
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import org.gvsig.fmap.dal.resource.ResourceNotification; |
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import org.gvsig.fmap.dal.resource.ResourceParameters; |
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import org.gvsig.fmap.dal.resource.exception.AccessResourceException; |
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import org.gvsig.fmap.dal.resource.exception.PrepareResourceException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceExecuteException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceNotifyChangesException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceNotifyCloseException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceNotifyDisposeException; |
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import org.gvsig.fmap.dal.resource.exception.ResourceNotifyOpenException; |
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import org.gvsig.fmap.dal.resource.impl.DefaultResourceNotification; |
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import org.gvsig.tools.observer.Observer; |
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import org.gvsig.tools.observer.WeakReferencingObservable; |
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import org.gvsig.tools.observer.impl.BaseWeakReferencingObservable; |
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import org.gvsig.tools.observer.impl.DelegateWeakReferencingObservable; |
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import org.slf4j.Logger; |
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import org.slf4j.LoggerFactory; |
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/**
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* <p>
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* Base implementation for Resource
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* </p>
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*
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* <p>
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* This implementation not define the {@link Resource#begin()} and
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* {@link Resource#end()}
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* </p>
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*
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* @author jmvivo
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*
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*/
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public abstract class AbstractResource implements ResourceProvider, |
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WeakReferencingObservable { |
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private static Logger logger = LoggerFactory.getLogger(AbstractResource.class); |
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private DelegateWeakReferencingObservable delegateObservable;
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private List consumers; |
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private long lastTimeOpen; |
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private long lastTimeUsed; |
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private ResourceParameters parameters;
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private ResourceParameters preparedParameters;
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private Object data; |
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private int openCount; |
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/**
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* Number of times an execute is being simultaneously performed with this
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* resource.
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*/
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private int executeCount = 0; |
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protected final Object lock; |
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protected Object multiResourcelock; |
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protected AbstractResource(ResourceParameters parameters)
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throws InitializeException {
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consumers = new ArrayList(); |
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lastTimeOpen = System.currentTimeMillis();
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lastTimeUsed = lastTimeOpen; |
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openCount = 0;
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preparedParameters = null;
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delegateObservable = new DelegateWeakReferencingObservable(this); |
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lock = new Object(); |
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multiResourcelock = new Object(); |
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this.parameters = null; |
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if( parameters != null ) { |
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try {
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this.parameters = (ResourceParameters) parameters.getCopy();
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} catch (CopyParametersException e) {
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throw new InitializeException(e); |
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} |
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} |
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} |
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protected final void updateLastTimeUsed() { |
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lastTimeUsed = System.currentTimeMillis();
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} |
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protected final void updateLastTimeOpen() { |
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lastTimeOpen = System.currentTimeMillis();
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lastTimeUsed = lastTimeOpen; |
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} |
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public final long getLastTimeOpen() { |
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return lastTimeOpen;
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} |
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public final long getLastTimeUsed() { |
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return lastTimeUsed;
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} |
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public ResourceParameters getParameters() {
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if (preparedParameters != null) { |
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return preparedParameters;
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} |
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return this.parameters; |
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} |
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public void prepare(ResourceParameters params) |
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throws PrepareResourceException {
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ResourceNotification notification = |
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new DefaultResourceNotification(this, |
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ResourceNotification.PREPARE, params); |
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this.delegateObservable.notifyObservers(notification);
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} |
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public void prepare() throws PrepareResourceException { |
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if (preparedParameters == null && this.parameters!=null ) { |
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try {
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ResourceParameters params = |
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(ResourceParameters) parameters.getCopy(); |
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prepare(params); |
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preparedParameters = params; |
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} catch (CopyParametersException e) {
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throw new PrepareResourceException(this, e); |
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} |
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} |
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} |
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public void notifyOpen() throws ResourceNotifyOpenException { |
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this.notifyObserver(ResourceNotification.OPEN);
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updateLastTimeOpen(); |
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openCount++; |
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} |
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public void notifyClose() throws ResourceNotifyCloseException { |
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if (openCount <= 0) { |
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try {
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throw new IllegalStateException(); |
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} catch(IllegalStateException ex) { |
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logger.warn("notify close in a resource already closed ("+this.parameters==null? "null": this.parameters.toString()+").", ex); |
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} |
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this.notifyObserver(ResourceNotification.CLOSE);
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} else {
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this.notifyObserver(ResourceNotification.CLOSE);
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openCount--; |
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} |
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} |
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public void notifyChanges() throws ResourceNotifyChangesException { |
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this.notifyObserver(ResourceNotification.CHANGED);
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Iterator it = consumers.iterator();
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while (it.hasNext()) {
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ResourceConsumer consumer = |
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(ResourceConsumer) ((WeakReference) it.next()).get();
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if (consumer != null) { |
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consumer.resourceChanged(this);
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} else {
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it.remove(); |
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} |
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} |
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} |
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public boolean isOpen() { |
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return this.openCount > 0; |
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} |
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public int openCount() { |
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return this.openCount; |
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} |
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public void addObserver(Observer o) { |
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this.delegateObservable.addObserver(o);
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} |
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public void deleteObserver(Observer o) { |
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this.delegateObservable.deleteObserver(o);
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} |
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public void deleteObservers() { |
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this.delegateObservable.deleteObservers();
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} |
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public final void addObservers(BaseWeakReferencingObservable observers) { |
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this.delegateObservable.addObservers(observers);
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} |
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public final void addConsumer(ResourceConsumer consumer) { |
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this.updateConsumersList();
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consumers.add(new WeakReference(consumer)); |
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} |
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public final void removeConsumer(ResourceConsumer consumer) { |
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ResourceConsumer cur; |
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Iterator it = consumers.iterator();
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while (it.hasNext()) {
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cur = (ResourceConsumer) ((WeakReference) it.next()).get();
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if (cur == null || (cur == consumer)) { |
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it.remove(); |
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} |
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} |
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} |
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public int getConsumersCount() { |
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this.updateConsumersList();
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return consumers.size();
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} |
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public ResourceConsumer getConsumerAt(int i){ |
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this.updateConsumersList();
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if (consumers==null){ |
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return null; |
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}else{
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return (ResourceConsumer)consumers.get(i);
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} |
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} |
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private synchronized void updateConsumersList() { |
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Iterator it = consumers.iterator();
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WeakReference ref;
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while (it.hasNext()) {
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ref = (WeakReference) it.next();
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if (ref.get() == null) { |
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it.remove(); |
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} |
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} |
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} |
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public void closeRequest() throws ResourceException { |
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if (inUse()) {
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return;
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} |
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if (consumers != null) { |
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Iterator it = consumers.iterator();
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while (it.hasNext()) {
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ResourceConsumer consumer = |
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(ResourceConsumer) ((WeakReference) it.next()).get();
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if (consumer != null) { |
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consumer.closeResourceRequested(this);
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} else {
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it.remove(); |
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} |
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} |
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} |
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} |
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public void setData(Object data) { |
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this.data = data;
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} |
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public Object getData() { |
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return this.data; |
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} |
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protected void notifyObserver(String type) { |
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if (delegateObservable != null) { |
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this.delegateObservable.notifyObservers(new DefaultResourceNotification( |
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this, type));
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} |
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} |
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public void notifyDispose() throws ResourceNotifyDisposeException { |
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this.notifyObserver(ResourceNotification.DISPOSE);
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if (consumers != null) { |
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consumers.clear(); |
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} |
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lastTimeOpen = 0l;
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lastTimeUsed = 0l;
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data = null;
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if (delegateObservable != null) { |
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delegateObservable.deleteObservers(); |
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} |
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} |
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public final boolean inUse() { |
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return executeCount > 0; |
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} |
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public Object execute(ResourceAction action) |
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throws ResourceExecuteException {
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Object value = null; |
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synchronized (lock) {
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synchronized (multiResourcelock) {
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executeBegins(); |
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try {
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value = performExecution(action); |
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} catch (Exception e) { |
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throw new ResourceExecuteException(this, e); |
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} finally {
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executeEnds(); |
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} |
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} |
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} |
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return value;
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} |
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protected Object performExecution(ResourceAction action) throws Exception { |
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return action.run();
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} |
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protected final void executeBegins() { |
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executeCount++; |
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} |
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protected final void executeEnds() { |
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updateLastTimeUsed(); |
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executeCount--; |
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} |
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/**
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* Returns the name of the {@link Resource}.
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*
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* @throws AccessResourceException
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* if there is an error while accessing the resource
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*/
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public abstract String getName() throws AccessResourceException; |
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/**
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* Returns the real resource represented by this object.
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*
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* @throws AccessResourceException
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* if there is an error while accessing the resource
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*/
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public abstract Object get() throws AccessResourceException; |
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} |