Java example source code file (EntityManagerPerRequestProvisionTest.java)

This example Java source code file (EntityManagerPerRequestProvisionTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

duplicate, entitymanager, entitymanagerperrequestprovisiontest, injector, jpadao, jpapersistmodule, jpatestentity, override, persisting, testcase, transactional

The EntityManagerPerRequestProvisionTest.java Java example source code

/**
 * Copyright (C) 2010 Google, Inc.
 *
 * 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 com.google.inject.persist.jpa;

import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.persist.PersistService;
import com.google.inject.persist.Transactional;
import com.google.inject.persist.UnitOfWork;

import junit.framework.TestCase;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;

/**
 * A test around providing sessions (starting, closing etc.)
 *
 * @author Dhanji R. Prasanna (dhanji@gmail.com)
 */

public class EntityManagerPerRequestProvisionTest extends TestCase {
  private Injector injector;

  @Override
  public void setUp() {
    injector = Guice.createInjector(new JpaPersistModule("testUnit"));

    //startup persistence
    injector.getInstance(PersistService.class).start();

    injector.getInstance(UnitOfWork.class).begin();
  }

  @Override
  public final void tearDown() {
    injector.getInstance(UnitOfWork.class).end();
    injector.getInstance(EntityManagerFactory.class).close();
  }

  public void testEntityManagerLifecyclePerTxn() {
    //obtain em
    JpaDao dao = injector.getInstance(JpaDao.class);

    //obtain same em again (bound to txn)
    JpaTestEntity te = new JpaTestEntity();

    dao.persist(te);

    //im not sure this hack works...
    assertEquals("Entity managers closed inside same thread-scope",
        injector.getInstance(EntityManager.class), JpaDao.em);

    //try to start a new em in a new txn
    dao = injector.getInstance(JpaDao.class);

    assertTrue("EntityManager was closed and reopened around txn"
        + " (persistent object does not persist)", dao.contains(te));
  }

  public void testEntityManagerLifecyclePerTxn2() {
    //obtain em
    JpaDao dao = injector.getInstance(JpaDao.class);

    //obtain same em again (bound to txn)
    JpaTestEntity te = new JpaTestEntity();

    dao.persist(te);

    //im not sure this hack works...
    assertEquals("Duplicate entity managers crossing-scope",
        injector.getInstance(EntityManager.class), JpaDao.em);
    assertEquals("Duplicate entity managers crossing-scope",
        injector.getInstance(EntityManager.class), JpaDao.em);

    //try to start a new em in a new txn
    dao = injector.getInstance(JpaDao.class);

    assertTrue("EntityManager was closed and reopened around txn"
        + " (persistent object doesnt persist)", dao.contains(te));
  }

  public static class JpaDao {
    static EntityManager em;

    @Inject
    public JpaDao(EntityManager em) {
      JpaDao.em = em;
    }

    @Transactional
    public <T> void persist(T t) {
      assertTrue("em is not open!", em.isOpen());
      assertTrue("no active txn!", em.getTransaction().isActive());
      em.persist(t);

      assertTrue("Persisting object failed", em.contains(t));
    }

    @Transactional
    public <T> boolean contains(T t) {
      return em.contains(t);
    }
  }
}