Application: gvSIG desktop

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

import java.lang.ref.WeakReference;

import java.util.Base64;

import javax.json.JsonObject;

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

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

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

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

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

import org.gvsig.fmap.dal.feature.spi.FeatureReferenceProviderServices;

import org.gvsig.json.Json;

import org.gvsig.json.JsonObjectBuilder;

import org.gvsig.tools.persistence.Persistent;

import org.gvsig.tools.persistence.PersistentState;

import org.gvsig.tools.persistence.exception.PersistenceException;

/**

 *

 * @author fdiaz

 */

public class FeatureReferenceCounter implements FeatureReferenceProviderServices, Persistent {

    public static final String COUNTER_TYPE = "counter";

    private static long counter = -1;

    private long oid;

    private WeakReference storeRef;

    private String featureTypeId;

    /*friend*/

    FeatureReferenceCounter(FeatureStore store) {

        this.oid = counter--;

            this.storeRef = new WeakReference(store);

        this.featureTypeId = store.getDefaultFeatureTypeQuietly().getId();

    }

    FeatureReferenceCounter(FeatureStore store, Object oid) {

        if(!(oid instanceof Number)){

            throw new IllegalArgumentException("oid must be a number");

        }

        if(((Number) oid).longValue() >=  0){

            throw new IllegalArgumentException("oid must be less than zero  ("+oid+").");

        }

        this.oid = ((Number) oid).longValue();

            this.storeRef = new WeakReference(store);

        this.featureTypeId = store.getDefaultFeatureTypeQuietly().getId();

    }

    /*friend*/

    FeatureReferenceCounter(FeatureStore store, JsonObject code) {

            this.storeRef = new WeakReference(store);

        this.featureTypeId = store.getDefaultFeatureTypeQuietly().getId();

        this.oid = (Long)Json.toObject(code, "oid");

    }

    public FeatureReferenceCounter() {

        //For persistence use only

    }

    @Override

    public Object getOID() {

        return  this.oid;

    }

    @Override

    public String[] getKeyNames() {

        return null;

    }

    @Override

    public Object getKeyValue(String name) {

        return null;

    }

    @Override

    public String getFeatureTypeId() {

        return featureTypeId;

    }

    @Override

    public Feature getFeature() throws DataException {

        return this.getStore().getFeatureByReference(this);

    }

    @Override

    public Feature getFeatureQuietly() {

        try {

            return this.getFeature();

        } catch (Exception e) {

            return null;

        }

    }

    @Override

    public Feature getFeature(FeatureType featureType) throws DataException {

        return this.getStore().getFeatureByReference(this, featureType);

    }

    private DefaultFeatureStore getStore() {

        return (DefaultFeatureStore) this.storeRef.get();

    }

    @Override

    public boolean isNewFeature() {

        return true;

    }

    @Override

    public String getCode() {

        JsonObjectBuilder builder = Json.createObjectBuilder();

        builder.add("type", COUNTER_TYPE);

        builder.add("oid", this.oid);

        String s = builder.toString();

        String r = Base64.getEncoder().encodeToString(s.getBytes());

        return r;

    }

    @Override

    public void saveToState(PersistentState state) throws PersistenceException {

        state.set("type", COUNTER_TYPE);

        state.set("oid", oid);

        state.set("store", (Persistent) storeRef.get());

        state.set("featureTypeId", featureTypeId);

        state.set("isNewFeature", isNewFeature());

    }

    @Override

    public void loadFromState(PersistentState state)

            throws PersistenceException {

        this.oid = state.getLong("oid");

        this.storeRef = new WeakReference(state.get("store"));

        this.featureTypeId = state.getString("featureTypeId");

    }

    @Override

    public boolean equals(Object obj) {

        if (!(obj instanceof FeatureReferenceCounter)) {

            return false;

        }

        FeatureReferenceCounter other = (FeatureReferenceCounter) obj;

        FeatureStore otherStore = (FeatureStore) other.storeRef.get();

        FeatureStore myrStore = (FeatureStore) this.storeRef.get();

        if (otherStore == null || myrStore == null) {

            return false;

        }

        if (!myrStore.equals(otherStore)) {

            return false;

        }

        if (this.oid == other.oid){

            return true;

        }

        return this.oid == other.oid;

    }

    @Override

    public int hashCode() {

        return Long.hashCode(this.oid);

    }

    public static boolean canUse(Object oid){

        if(oid instanceof Number){

            if(((Number) oid).longValue() <  0){

                return true;

            }

        }

        return false;

    }

}