Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.feature.impl.featureset;

import java.util.Iterator;

import javax.json.Json;

import javax.json.JsonArray;

import javax.json.JsonArrayBuilder;

import javax.json.JsonObject;

import org.gvsig.fmap.dal.DataStore;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.dal.feature.FeatureSet;

import org.gvsig.fmap.dal.feature.FeatureStore;

import org.gvsig.fmap.dal.feature.impl.DefaultFeature;

import org.gvsig.fmap.dal.feature.impl.dynobjectutils.DynObjectSetFeatureSetFacade;

import org.gvsig.tools.dispose.DisposableIterator;

import org.gvsig.tools.dispose.DisposeUtils;

import org.gvsig.tools.dynobject.DynObjectSet;

import org.gvsig.tools.exception.BaseException;

import org.gvsig.tools.visitor.VisitCanceledException;

import org.gvsig.tools.visitor.Visitor;

import org.gvsig.tools.visitor.impl.AbstractIndexedVisitable;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public abstract class AbstractFeatureSet 

    extends AbstractIndexedVisitable 

    implements FeatureSet {

    private static class DisposableSetIteratorImpl implements DisposableSetIterator {

        private final FeatureSet fset;

        private final DisposableIterator it;

        public DisposableSetIteratorImpl(FeatureSet fset, DisposableIterator it) {

            this.fset = fset;

            this.it = it;

        }

        @Override

        public boolean hasNext() {

            return this.it.hasNext();

        }

        @Override

        public Feature next() {

            return (Feature) this.it.next();

        }

        @Override

        public Iterator<Feature> iterator() {

            return this.it;

        }

        @Override

        public void dispose() {

            DisposeUtils.disposeQuietly(this.it);

            DisposeUtils.disposeQuietly(this.fset);

        }

    } 

    protected static final Logger LOG = LoggerFactory.getLogger(AbstractFeatureSet.class);

    public abstract FeatureStore getFeatureStore();

    @Override

    public final void accept(Visitor visitor, long firstValueIndex, long elements) throws BaseException {

        try {

            doAccept(visitor, firstValueIndex, elements);

        } catch (VisitCanceledException ex) {

            // The visit has been cancelled by the visitor, so we finish here.

            LOG.debug(

                    "The visit, beggining on position {}, has been cancelled "

                    + "by the visitor: {}", new Long(firstValueIndex),

                    visitor);

        }

    }

    @Override

    protected void doAccept(Visitor visitor, long firstValueIndex)

        throws VisitCanceledException, BaseException {

        doAccept(visitor, firstValueIndex, 0);

    }

    protected void doAccept(Visitor visitor, long firstValueIndex, long elements)

        throws VisitCanceledException, BaseException {

        DisposableIterator iterator = fastIterator(firstValueIndex, elements);

        try {

            while (iterator.hasNext()) {

                Feature feature = (Feature) iterator.next();

                visitor.visit(feature);

            }

        } finally {

            iterator.dispose();

        }

    }

    @Override

    public Feature first() {

        DisposableIterator it = null;

        try {

            it = this.iterator();

            if( it == null ) {

                return null;

            }

            if( it.hasNext() ) {

                Feature f = (Feature) it.next();

                return f;

            }

            return null;

        } finally {

            DisposeUtils.disposeQuietly(it);

        }

    }

    @Override

    public boolean isEmpty() throws DataException {

        return this.getSize() == 0;

    }

    @Override

    public DisposableIterator fastIterator() throws DataException {

        return this.fastIterator(0);

    }   

    @Override

    public DisposableIterator iterator() {

        try {

            return this.fastIterator(0);

        } catch (DataException ex) {

            throw new RuntimeException("Can't obtain itertor.",ex);

        }

    }

    @Override

    public DisposableSetIterator setIterator() {

        return new DisposableSetIteratorImpl(this, this.iterator());

    }

    @Override

    public DynObjectSet getDynObjectSet() {

        return this.getDynObjectSet(true);

    }

    @Override

    public DynObjectSet getDynObjectSet(boolean fast) {

        return new DynObjectSetFeatureSetFacade(this, this.getFeatureStore(), fast);

    }

    @Override

    public boolean isFromStore(DataStore store) {

        return this.getFeatureStore().equals(store);

    }    

    @Override

    public long size64() {

        try {

            return this.getSize();

        } catch (DataException ex) {

            throw new RuntimeException("Can't get size",ex);

        }

    }

    @Override

    public int size() {

        try {

            long sz = this.getSize();

            if( sz > Integer.MAX_VALUE ) {

                return Integer.MAX_VALUE;

            }

            return (int) sz;

        } catch (DataException ex) {

            throw new RuntimeException("Can't get size",ex);

        }

    }

    public JsonArray toJSON() {

        // TODO: estaria bien hacer una implementacion alternativa que devolviese

        // un JsonArray basado en el FeatureSet/FeaturePagingHelper, asi no 

        // tendria que construirse en memoria el JSON entero.

        try {

            JsonArrayBuilder builder = Json.createArrayBuilder();

            this.accept(new Visitor() {

                @Override

                public void visit(Object obj) throws VisitCanceledException, BaseException {

                    DefaultFeature f = (DefaultFeature) obj;

                    JsonObject fjson = f.toJSON();

                    builder.add(fjson);

                }

            });

            return builder.build();        

        } catch (Exception ex) {

            throw new RuntimeException("Can't create JSON array.",ex);

        }

    }

}