nh.examples.springintegration.order.framework.domain.Repository.java Source code

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Here is the source code for nh.examples.springintegration.order.framework.domain.Repository.java

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/**********************************************************************
 * Copyright (c) 2010 Nils Hartmann 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
 *
 * Contributors:
 *     Nils Hartmann initial implementation
 **********************************************************************/
package nh.examples.springintegration.order.framework.domain;

import static com.google.common.base.Preconditions.checkNotNull;
import static java.lang.String.format;

import java.lang.reflect.ParameterizedType;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityNotFoundException;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

/**
 * @author Nils Hartmann (nils@nilshartmann.net)
 * 
 */
public abstract class Repository<T extends AggregateRoot> {

    Logger _logger = LoggerFactory.getLogger(getClass());

    @PersistenceContext
    private EntityManager _entityManager;

    /**
     * Saves the given aggregate root.
     * 
     * @param aggregateRoot
     */
    @Transactional(propagation = Propagation.MANDATORY)
    public void save(T aggregateRoot) {
        checkNotNull(aggregateRoot);

        _logger.info("Saving {}", aggregateRoot);

        _entityManager.persist(aggregateRoot);
    }

    public T getById(EntityIdentifier entityIdentifier) {
        checkNotNull(entityIdentifier);

        T aggregateRoot = _entityManager.find(getAggregateType(), entityIdentifier);

        if (aggregateRoot == null) {
            throw new EntityNotFoundException(format("Aggregate with id '{}' not found", entityIdentifier));
        }

        return aggregateRoot;

    }

    public List<T> getAll() {
        TypedQuery<T> query = _entityManager
                .createQuery(format("SELECT o FROM %s o", getAggregateType().getSimpleName()), getAggregateType());
        return query.getResultList();
    }

    private Class<T> getAggregateType() {
        @SuppressWarnings("unchecked")
        Class<T> clazz = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass())
                .getActualTypeArguments()[0];
        return clazz;
    }
}