org.geotools.data.FeatureLocking Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of gt-main Show documentation

The main module contains the GeoTools public interfaces that are used by other GeoTools modules (and GeoTools applications). Where possible we make use industry standard terms as provided by OGC and ISO standards. The formal GeoTools public api consists of gt-metadata, jts and the gt-main module. The main module contains the default implementations that are available provided to other GeoTools modules using our factory system. Factories are obtained from an appropriate FactoryFinder, giving applications a chance configure the factory used using the Factory Hints facilities. FilterFactory ff = CommonFactoryFinder.getFilterFactory(); Expression expr = ff.add( expression1, expression2 ); If you find yourself using implementation specific classes chances are you doing it wrong: Expression expr = new AddImpl( expression1, expressiom2 );

The newest version!

/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    This library 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;
 *    version 2.1 of the License.
 *
 *    This library 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.
 */
package org.geotools.data;

import java.io.IOException;
import java.util.Set;
import org.opengis.feature.Feature;
import org.opengis.feature.type.FeatureType;
import org.opengis.filter.Filter;

/**
 * Provides Feature based locking.
 *
 * 
 * Features from individual shapefiles, database tables, etc. can be protected
 * or reserved from modification through this interface.
 * 
 * 
 * To use please cast your SimpleFeatureSource to this interface.
 * 

 * SimpleFeatureSource source = dataStore.getFeatureSource("roads");
 * if( source instanceof FeatureLocking ) {
 *     FeatureLocking locking = (FeatureLocking) source;
 *     ...
 * }
 *
 * @author Jody Garnett, Refractions Research, Inc.
 * @author Ray Gallagher
 * @author Rob Hranac, TOPP
 * @author Chris Holmes, TOPP
 *
 *
 *
 * @version $Id$
 */
public interface FeatureLocking
        extends FeatureStore {
    /**
     * All locking operations will operate against the provided lock.
     *
     * This in in keeping with the stateful spirit of DataSource in which operations are against
     * the "current" transaction. If a FeatureLock is not provided lock operations will only be
     * applicable for the current transaction (they will expire on the next commit or rollback).
     *
     * 
That is lockFeatures() operations will:
     *
     * 

     *   Be recorded against the provided FeatureLock.
     *   
Be recorded against the current transaction if no FeatureLock is provided.
     * 
     *
     * Calling this method with setFeatureLock( FeatureLock.TRANSACTION
     * ) will revert to per transaction operation.
     *
     * 
This design allows for the following:
     *
     * 

     *   cross DataSource FeatureLock usage
     *   
not having pass in the same FeatureLock object multiple times
     * 
     *
     * @param lock FeatureLock configuration including authorization and requested duration
     */
    void setFeatureLock(FeatureLock lock);

    /**
     * FeatureLock features described by Query.
     *
     * To implement WFS parcial Locking retrieve your features with a query operation first
     * before trying to lock them individually. If you are not into WFS please don't ask what
     * parcial locking is.
     *
     * @param query Query describing the features to lock
     * @return Number of features locked
     * @throws IOException Thrown if anything goes wrong
     */
    int lockFeatures(Query query) throws IOException;

    /**
     * FeatureLock features described by Filter.
     *
     * 
To implement WFS parcial Locking retrieve your features with a query operation first
     * before trying to lock them individually. If you are not into WFS please don't ask what
     * parcial locking is.
     *
     * @param filter Filter describing the features to lock
     * @return Number of features locked
     * @throws IOException Thrown if anything goes wrong
     */
    int lockFeatures(Filter filter) throws IOException;

    /**
     * FeatureLock all Features.
     *
     * 
The method does not prevent addFeatures() from being used (we could add a lockDataSource()
     * method if this functionality is required.
     *
     * @return Number of Features locked by this opperation
     */
    int lockFeatures() throws IOException;

    /**
     * Unlocks all Features.
     *
     * 
Authorization must be provided prior before calling this method.
     *
     * 

     * void releaseLock( String lockId, LockingDataSource ds ){
     *    ds.setAuthorization( "LOCK534" );
     *    ds.unLockFeatures();
     * }
     * 
     */
    void unLockFeatures() throws IOException;

    /**
     * Unlock Features denoted by provided filter.
     *
     * Authorization must be provided prior before calling this method.
     */
    void unLockFeatures(Filter filter) throws IOException;

    /**
     * Unlock Features denoted by provided query.
     *
     * Authorization must be provided prior before calling this method.
     *
     * @param query Specifies fatures to unlock
     */
    void unLockFeatures(Query query) throws IOException;

    /** Idea for a response from a high-level lock( Query ) function. */
    public static class Response {
        String authID;
        Set locked;
        Set notLocked;

        public Response(FeatureLock lock, Set lockedFids, Set notLockedFids) {
            authID = lock.getAuthorization();
            locked = lockedFids;
            notLocked = notLockedFids;
        }

        public String getAuthorizationID() {
            return authID;
        }

        public Set getLockedFids() {
            return locked;
        }

        public Set getNotLockedFids() {
            return notLocked;
        }
    }
}