org.opendaylight.persistence.common.query.PagedFindQuery Maven / Gradle / Ivy

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/**
 * Copyright (c) 2015 Hewlett-Packard Development Company, L.P. and others. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.persistence.common.query;

import java.util.List;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import org.opendaylight.persistence.DataStore;
import org.opendaylight.persistence.PersistenceException;
import org.opendaylight.persistence.Query;
import org.opendaylight.persistence.dao.PagedDao;
import org.opendaylight.persistence.util.common.type.Sort;
import org.opendaylight.persistence.util.common.type.page.Page;
import org.opendaylight.persistence.util.common.type.page.PageRequest;
import org.opendaylight.yangtools.concepts.Identifiable;

/**
 * Query to get a page of objects from the data store that match the given filter.
 * 
 * @param  type of the identifiable object (object to store in the data store)
 * @param  type of the associated filter
 * @param  type of the associated sort attribute or sort key used to construct sort
 *            specifications
 * @param  type of the page request
 * @param  type of the page
 * @param  type of the query's execution context; the context managed by the {@link DataStore}
 * @author Fabiel Zuniga
 * @author Nachiket Abhyankar
 */
public final class PagedFindQuery, F, S, R extends PageRequest, D extends Page, C>
        implements Query {

    private F filter;
    private List> sort;
    private R pageRequest;
    private PagedDao dao;

    private PagedFindQuery(@Nonnull F filter, @Nullable List> sort, @Nonnull R pageRequest,
            @Nonnull PagedDao dao) {
        this.filter = filter;
        this.sort = sort;
        this.pageRequest = pageRequest;
        this.dao = dao;
    }

    /**
     * Creates a query.
     * 
     * This method is a convenience to infer the generic types.
     * 
     * @param filter filter
     * @param sort sort specification
     * @param pageRequest page request
     * @param dao DAO to assist the query
     * @return the query
     */
    public static , F, S, R extends PageRequest, D extends Page, C> Query createQuery(
            @Nonnull F filter, @Nullable List> sort, @Nonnull R pageRequest,
            @Nonnull PagedDao dao) {
        return new PagedFindQuery(filter, sort, pageRequest, dao);
    }

    @Override
    public D execute(C context) throws PersistenceException {
        return this.dao.find(this.filter, this.sort, this.pageRequest, context);
    }
}