org.ctoolkit.restapi.client.provider.LocalResourceProvider Maven / Gradle / Ivy

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/*
 * Copyright (c) 2016 Comvai, s.r.o. All Rights Reserved.
 *
 * 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; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package org.ctoolkit.restapi.client.provider;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;

/**
 * The interface that provides possibility to plug-in right before a remote resource retrieval (either get or list).
 * The implementation of concrete type is optional and will be used once binded in guice configuration.
 * 
 * To bind a concrete implementation use this in your guice module: 
{@code
 *  bind( new TypeLiteral>(){} )
 *      .to( MyResourceProvider.class );
 * }
 *
 * @param  the type of the resource
 * @author Aurel Medvegy
 */
public interface LocalResourceProvider
{
    /**
     * Retrieve a local resource to avoid a remote call.
     * Note: if this method returns null it will make call of {@link #persist(Object, Object, Map, Locale)}
     * once a remote resource call returns a non null value. Processed in the same thread.
     *
     * @param identifier       the unique identifier of the resource
     * @param parameters       the optional resource parameters
     * @param locale           the language the client has configured to prefer in results if applicable
     * @param lastModifiedDate the last modified date of the remote resource if any
     * @return the locally cached or stored resource if exist, otherwise returns null
     */
    T get( Object identifier,
           @Nullable Map parameters,
           @Nullable Locale locale,
           @Nullable Date lastModifiedDate );

    /**
     * Optionally, persist the resource instance as a result of the remote call.
     * This method will be called in case if {@link #get(Object, Map, Locale, Date)}
     * returns null and for a non null result of the remote call. Processed in the same thread.
     * 
     * Note: prefer asynchronous implementation.
     *
     * @param instance   the resource instance to be either persisted or cached
     * @param identifier the unique identifier of the resource
     * @param parameters the optional resource parameters
     * @param locale     the language the client has configured to prefer in results if applicable
     */
    void persist( @Nonnull T instance,
                  @Nullable Object identifier,
                  @Nullable Map parameters,
                  @Nullable Locale locale );

    /**
     * Retrieve a local list of resource to avoid a remote call.
     * Note: if this method returns null it will make call of {@link #persistList(List, Map, Locale)}
     * once a remote resource call returns a non null value. Processed in the same thread.
     *
     * @param parameters       the optional resource parameters
     * @param locale           the language the client has configured to prefer in results if applicable
     * @param lastModifiedDate the last modified date of the remote resource if any
     * @return the locally cached or stored resource if exist, otherwise returns null
     */
    List list( @Nullable Map parameters,
                  @Nullable Locale locale,
                  @Nullable Date lastModifiedDate );

    /**
     * Optionally, persist the resource instance as a result of the remote call.
     * This method will be called in case if {@link #list(Map, Locale, Date)}
     * returns null and for a non null result of the remote call. Processed in the same thread.
     * 
     * Note: prefer asynchronous implementation.
     *
     * @param instance   the resource instance to be either persisted or cached
     * @param parameters the optional resource parameters
     * @param locale     the language the client has configured to prefer in results if applicable
     */
    void persistList( @Nonnull List instance,
                      @Nullable Map parameters,
                      @Nullable Locale locale );
}