JpaFindByIdAccessImpl.java

/*
 * Copyright 2007 The Fornax Project Team, including the original
 * author or authors.
 *
 * 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.sculptor.framework.accessimpl.jpa;

import java.io.Serializable;

import javax.persistence.LockModeType;
import javax.persistence.PersistenceException;

import org.sculptor.framework.accessapi.FindByIdAccess;

/**
 * <p>
 * Find an entity by its id. Implementation of Access command FindByIdAccess.
 * </p>
 * <p>
 * Command design pattern.
 * </p>
 */
public class JpaFindByIdAccessImpl<T, ID extends Serializable> extends JpaAccessBase<T> implements
		FindByIdAccess<T, ID> {

	private boolean lock;
	private ID id;
	private T result;

	public JpaFindByIdAccessImpl(Class<T> persistentClass) {
		setPersistentClass(persistentClass);
	}

	protected boolean isLock() {
		return lock;
	}

	public void setLock(boolean lock) {
		this.lock = lock;
	}

	protected ID getId() {
		return id;
	}

	public void setId(ID id) {
		this.id = id;
	}

	public T getResult() {
		return result;
	}

	protected void setResult(T result) {
		this.result = result;
	}

	public void performExecute() throws PersistenceException {
		result = (T) getEntityManager().find(getPersistentClass(), id);
		if (lock) {
			// use pessimistic locking strategy
			getEntityManager().lock(result, LockModeType.WRITE);
		}
	}

}