core/api/src/main/java/org/apache/zest/api/unitofwork/UnitOfWorkFactory.java

/*
 * Copyright (c) 2007, Rickard Öberg. All Rights Reserved.
 * Copyright (c) 2007, Niclas Hedhman. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.apache.zest.api.unitofwork;

import org.apache.zest.api.entity.EntityComposite;
import org.apache.zest.api.usecase.Usecase;

/**
 * Factory for UnitOfWork.
 */
public interface UnitOfWorkFactory
{
    /**
     * Create a new UnitOfWork and associate it with the current thread.
     * <p>
     * The UnitOfWork will use the default Usecase settings.
     * </p>
     * <p>
     * Current time will be set to System.currentTimeMillis();
     * </p>
     * @return a new UnitOfWork
     */
    UnitOfWork newUnitOfWork();

    /**
     * Create a new UnitOfWork and associate it with the current thread.
     * <p>
     * The UnitOfWork will use the default Usecase settings.
     * </p>
     * @return a new UnitOfWork
     */
    UnitOfWork newUnitOfWork( long currentTime );

    /**
     * Create a new UnitOfWork for the given Usecase and associate it with the current thread.
     * <p>
     * Current time will be set to System.currentTimeMillis();
     * </p>
     * @param usecase the Usecase for this UnitOfWork
     *
     * @return a new UnitOfWork
     */
    UnitOfWork newUnitOfWork( Usecase usecase );

    /**
     * Create a new UnitOfWork for the given Usecase and associate it with the current thread.
     *
     * @param usecase the Usecase for this UnitOfWork
     *
     * @return a new UnitOfWork
     */
    UnitOfWork newUnitOfWork( Usecase usecase, long currentTime );

    /**
     * @return true if there is an active UnitOfWork associated with the executing thread
     */
    boolean isUnitOfWorkActive();

    /**
     * Returns the UnitOfWork that is currently associated with the executing thread.
     *
     * @return The current UnitOfWork associated with the executing thread
     *
     * @throws IllegalStateException if no current UnitOfWork is active
     */
    UnitOfWork currentUnitOfWork()
        throws IllegalStateException;

    /**
     * Returns the UnitOfWork that the EntityComposite is bound to.
     *
     * @param entity the entity to be checked.
     *
     * @return The UnitOfWork instance that the Entity is bound to, or null if the entity is not associated with
     *         any UnitOfWork.
     */
    UnitOfWork getUnitOfWork( EntityComposite entity );
}