org.wisepersist.UserDao.java Source code

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Here is the source code for org.wisepersist.UserDao.java

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/*
 * Copyright (c) 2014 WisePersist
 *
 * 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.wisepersist;

import com.google.common.base.Optional;

import java.util.List;

import javax.persistence.Query;
import javax.persistence.TypedQuery;

/**
 * @author jiakuanwang
 */
public class UserDao extends AbstractDao {

    @Transactional
    public User saveUser(User user) {
        return em().merge(user);
    }

    @NonTransactional
    public Optional<User> findByEmail(String email) {
        TypedQuery<User> query = em().createQuery("SELECT user FROM User user WHERE user.email=:email", User.class);
        query.setParameter("email", email);
        List<User> users = query.getResultList();
        if (users.size() > 0) {
            return Optional.of(users.get(0));
        }
        return Optional.absent();
    }

    /**
     * This is a wrong method which should throw exception.
     */
    @Transactional
    public User nestedFindByEmail(String email) {
        Optional<User> userOpt = findByEmail(email);
        return userOpt.isPresent() ? userOpt.get() : null;
    }

    /**
     * Dangerous method for unit test only.
     */
    @Transactional
    protected synchronized int deleteAll() {
        Query query = em().createNativeQuery("DELETE FROM users");
        return query.executeUpdate();
    }
}