DataNucleus 3.0与Hibernate 3.5

如官方产品站点所述， DataNucleus Access Platform是现有的最符合标准的开源Java持久性产品。它完全符合JDO1 ， JDO2 ， JDO2.1 ， JDO2.2 ， JDO3 ， JPA1和JPA2 Java标准。它还符合OGC简单功能规范，以将地理空间Java类型保留到RDBMS。它使用基于OSGi的插件机制，这意味着它是非常可扩展的。

如产品官方“关于”页面所述， Hibernate是一种高性能的对象/关系持久性和查询服务。 Hibernate是市场上最灵活，功能最强大的对象/关系解决方案，它负责从Java类到数据库表以及从Java数据类型到SQL数据类型的映射。它提供了数据查询和检索功能，大大减少了开发时间。

出于本文的目的，我们将使用上述众所周知的产品作为持久性API的实际实现。我们的目标是能够比较对数据库应用CRUD（创建-检索-更新-删除）操作时的性能。

为此，我们将实现两个不同的基于Spring的WEB应用程序，这些应用程序将充当我们的“测试基础”。这两个应用程序的服务和数据访问层定义（接口和实现类）将完全相同。对于数据访问，我们将利用JPA2作为Java Persistence API。对于数据库，我们将使用嵌入式Derby实例。最后但并非最不重要的一点是，我们将针对以下所述的五个“基本”数据访问操作实施并执行相同的性能测试：

保持记录
通过其ID检索记录
检索所有记录
更新现有记录
删除记录

所有测试均针对具有以下特征的Sony Vaio进行：

系统：openSUSE 11.1（x86_64）
处理器（CPU）：Intel（R）Core（TM）2 Duo CPU T6670 @ 2.20GHz
处理器速度：1,200.00 MHz
总内存（RAM）：2.8 GB
Java：OpenJDK 1.6.0_0 64位

使用以下工具：

Spring框架3.0.1
Apache Derby 10.6.1.0
休眠 3.5.1
DataNucleus 3.0.0-m1
c3p0 0.9.1.2
Brent Boyer的Java Benchmarking框架

最终通知：

您可以在此处和此处下载两个“测试基础”的完整源代码。这些是基于Eclipse – Maven的项目。
为了能够自己编译和运行测试，您需要将Java Benchmarking框架二进制– jar文件安装到Maven存储库。另外，作为“一键式”解决方案，您可以使用我们创建的Java Benchmarking Maven软件包。您可以从此处下载它，然后将其解压缩到您的Maven存储库中，一切都很好。

“测试基地”…

我们将首先提供有关如何实施“测试基础”项目的信息。为了使我们的测试所针对的环境的细节清晰明了，这势在必行。如前所述，我们已经实现了两个基于Spring的多层WEB应用程序。在每个应用程序中，已经实现了两层，即服务层和数据访问层。这些层具有相同的定义-接口和实现细节。

我们的领域模型仅包含一个“雇员”对象。服务层提供了一个简单的“业务”服务，该服务公开了“员工”对象的CRUD（创建-检索-更新-删除）功能，而数据访问层则包括一个简单的数据访问对象，该对象利用Spring JpaDaoSupport抽象来提供与数据库的实际互操作性。

以下是数据访问层特定的类：

import javax.annotation.PostConstruct;
import javax.persistence.EntityManagerFactory;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;import com.javacodegeeks.springdatanucleus.dto.EmployeeDTO;@Repository("employeeDAO")
public class EmployeeDAO extends JpaDAO<Long, EmployeeDTO> {@AutowiredEntityManagerFactory entityManagerFactory;@PostConstructpublic void init() {super.setEntityManagerFactory(entityManagerFactory);}}

如您所见，我们的数据访问对象（DAO）扩展了JpaDAO类。该课程如下：

import java.lang.reflect.ParameterizedType;
import java.util.List;import javax.persistence.EntityManager;
import javax.persistence.PersistenceException;
import javax.persistence.Query;import org.springframework.orm.jpa.JpaCallback;
import org.springframework.orm.jpa.support.JpaDaoSupport;public abstract class JpaDAO<K, E> extends JpaDaoSupport {protected Class<E> entityClass;@SuppressWarnings("unchecked")public JpaDAO() {ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();this.entityClass = (Class<E>) genericSuperclass.getActualTypeArguments()[1];}public void persist(E entity) {getJpaTemplate().persist(entity);}public void remove(E entity) {getJpaTemplate().remove(entity);}public E merge(E entity) {return getJpaTemplate().merge(entity);}public void refresh(E entity) {getJpaTemplate().refresh(entity);}public E findById(K id) {return getJpaTemplate().find(entityClass, id);}public E flush(E entity) {getJpaTemplate().flush();return entity;}@SuppressWarnings("unchecked")public List<E> findAll() {Object res = getJpaTemplate().execute(new JpaCallback() {public Object doInJpa(EntityManager em) throws PersistenceException {Query q = em.createQuery("SELECT h FROM " +entityClass.getName() + " h");return q.getResultList();}});return (List<E>) res;}@SuppressWarnings("unchecked")public Integer removeAll() {return (Integer) getJpaTemplate().execute(new JpaCallback() {public Object doInJpa(EntityManager em) throws PersistenceException {Query q = em.createQuery("DELETE FROM " +entityClass.getName() + " h");return q.executeUpdate();}});}}

以下是我们的域类EmployeeDTO类：

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;@Entity
@Table(name = "EMPLOYEE")
public class EmployeeDTO implements java.io.Serializable {private static final long serialVersionUID = 7440297955003302414L;@Id@Column(name="employee_id")private long employeeId;@Column(name="employee_name", nullable = false, length=30)private String employeeName;@Column(name="employee_surname", nullable = false, length=30)private String employeeSurname;@Column(name="job", length=50)private String job;public EmployeeDTO() {}public EmployeeDTO(int employeeId) {this.employeeId = employeeId;  }public EmployeeDTO(long employeeId, String employeeName, String employeeSurname,String job) {this.employeeId = employeeId;this.employeeName = employeeName;this.employeeSurname = employeeSurname;this.job = job;}public long getEmployeeId() {return employeeId;}public void setEmployeeId(long employeeId) {this.employeeId = employeeId;}public String getEmployeeName() {return employeeName;}public void setEmployeeName(String employeeName) {this.employeeName = employeeName;}public String getEmployeeSurname() {return employeeSurname;}public void setEmployeeSurname(String employeeSurname) {this.employeeSurname = employeeSurname;}public String getJob() {return job;}public void setJob(String job) {this.job = job;}
}

最后但并非最不重要的是，下面提供了“业务”服务接口和实现类：

import java.util.List;import com.javacodegeeks.springdatanucleus.dto.EmployeeDTO;public interface EmployeeService {public EmployeeDTO findEmployee(long employeeId);public List<EmployeeDTO> findAllEmployees();public void saveEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception;public void updateEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception;public void saveOrUpdateEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception;public void deleteEmployee(long employeeId) throws Exception;}

import java.util.List;import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;import com.javacodegeeks.springdatanucleus.dao.EmployeeDAO;
import com.javacodegeeks.springdatanucleus.dto.EmployeeDTO;
import com.javacodegeeks.springdatanucleus.services.EmployeeService;@Service("employeeService")
public class EmployeeServiceImpl implements EmployeeService {@Autowiredprivate EmployeeDAO employeeDAO;@PostConstructpublic void init() throws Exception {}@PreDestroypublic void destroy() {}public EmployeeDTO findEmployee(long employeeId) {return employeeDAO.findById(employeeId);}public List<EmployeeDTO> findAllEmployees() {return employeeDAO.findAll();}@Transactional(propagation=Propagation.REQUIRED, rollbackFor=Exception.class)public void saveEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception {EmployeeDTO employeeDTO = employeeDAO.findById(employeeId);if(employeeDTO == null) {employeeDTO = new EmployeeDTO(employeeId, name,surname, jobDescription);employeeDAO.persist(employeeDTO);}}@Transactional(propagation=Propagation.REQUIRED, rollbackFor=Exception.class)public void updateEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception {EmployeeDTO employeeDTO = employeeDAO.findById(employeeId);if(employeeDTO != null) {employeeDTO.setEmployeeName(name);employeeDTO.setEmployeeSurname(surname);employeeDTO.setJob(jobDescription);}}@Transactional(propagation=Propagation.REQUIRED, rollbackFor=Exception.class)public void deleteEmployee(long employeeId) throws Exception {EmployeeDTO employeeDTO = employeeDAO.findById(employeeId);if(employeeDTO != null)employeeDAO.remove(employeeDTO);}@Transactional(propagation=Propagation.REQUIRED, rollbackFor=Exception.class)public void saveOrUpdateEmployee(long employeeId, String name, String surname, String jobDescription) throws Exception {EmployeeDTO employeeDTO = new EmployeeDTO(employeeId, name,surname, jobDescription);employeeDAO.merge(employeeDTO);}}

接下来是驱动Spring IoC容器的“ applicationContext.xml”文件。在两个“测试基础”项目之间，该文件的内容也相同。

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:task="http://www.springframework.org/schema/task"xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsdhttp://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsdhttp://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd"><context:component-scan base-package="com.javacodegeeks.springdatanucleus" /><tx:annotation-driven /><bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"><property name="persistenceUnitName" value="MyPersistenceUnit" /></bean><bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"><property name="entityManagerFactory" ref="entityManagerFactory" /></bean></beans>

为了能够从Servlet容器启动Spring应用程序（别忘了我们已经实现了基于Spring的WEB应用程序），我们在两个“测试基础”应用程序的“ web.xml”文件中都包含了以下侦听器：

<listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

这两个“测试基础”项目之间唯一不同的文件是定义要使用的Java持久性API（JPA）的实际实现的文件-“ persistence.xml”文件。以下是我们用来利用DataNucleus Access Platform的平台：

<persistence xmlns="http://java.sun.com/xml/ns/persistence"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"version="2.0"><persistence-unit name="MyPersistenceUnit" transaction-type="RESOURCE_LOCAL"><provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider><class>com.javacodegeeks.springdatanucleus.dto.EmployeeDTO</class><exclude-unlisted-classes>true</exclude-unlisted-classes><properties><property name="datanucleus.storeManagerType" value="rdbms"/><property name="datanucleus.ConnectionDriverName"  value="org.apache.derby.jdbc.EmbeddedDriver"/><property name="datanucleus.ConnectionURL" value="jdbc:derby:runtime;create=true"/><!-- <property name="datanucleus.ConnectionUserName" value=""/><property name="datanucleus.ConnectionPassword" value=""/>--><property name="datanucleus.autoCreateSchema" value="true"/><property name="datanucleus.validateTables" value="false"/><property name="datanucleus.validateConstraints" value="false"/><property name="datanucleus.connectionPoolingType" value="C3P0"/><property name="datanucleus.connectionPool.minPoolSize" value="5" /><property name="datanucleus.connectionPool.initialPoolSize" value="5" /><property name="datanucleus.connectionPool.maxPoolSize" value="20" /><property name="datanucleus.connectionPool.maxStatements" value="50" /></properties></persistence-unit></persistence>

接下来是用于将Hibernate用作JPA2实现框架的“ persistence.xml”文件：

<persistence xmlns="http://java.sun.com/xml/ns/persistence"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"version="2.0"><persistence-unit name="MyPersistenceUnit" transaction-type="RESOURCE_LOCAL"><provider>org.hibernate.ejb.hibernatePersistence</provider><class>com.javacodegeeks.springhibernate.dto.EmployeeDTO</class><exclude-unlisted-classes>true</exclude-unlisted-classes><properties><property name="hibernate.hbm2ddl.auto" value="update" /><property name="hibernate.show_sql" value="false" /><property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect" /><property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.EmbeddedDriver" /><property name="hibernate.connection.url" value="jdbc:derby:runtime;create=true" /><!-- <property name="hibernate.connection.username" value="" /><property name="hibernate.connection.password" value="" />--><property name="hibernate.c3p0.min_size" value="5" /><property name="hibernate.c3p0.max_size" value="20" /><property name="hibernate.c3p0.timeout" value="300" /><property name="hibernate.c3p0.max_statements" value="50" /><property name="hibernate.c3p0.idle_test_period" value="3000" /></properties></persistence-unit></persistence>

最后，我们演示实现所有要执行的测试用例的类。这两个“测试基础”项目的类是相同的：

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.fail;import java.util.List;
import java.util.concurrent.Callable;import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import bb.util.Benchmark;import com.javacodegeeks.springhibernate.dto.EmployeeDTO;
import com.javacodegeeks.springhibernate.services.EmployeeService;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"file:src/main/webapp/WEB-INF/applicationContext.xml"})
public class EmployeeServiceTest {@AutowiredEmployeeService employeeService;@Testpublic void testSaveEmployee() {try {employeeService.saveEmployee(1, "byron", "kiourtzoglou", "master software engineer");employeeService.saveEmployee(2, "ilias", "tsagklis", "senior software engineer");} catch (Exception e) {fail(e.getMessage());}}@Testpublic void testFindEmployee() {assertNotNull(employeeService.findEmployee(1));}@Testpublic void testFindAllEmployees() {assertEquals(employeeService.findAllEmployees().size(), 2);}@Testpublic void testUpdateEmployee() {try {employeeService.updateEmployee(1, "panagiotis", "paterakis", "senior software engineer");assertEquals(employeeService.findEmployee(1).getEmployeeName(), "panagiotis");} catch (Exception e) {fail(e.getMessage());}}@Testpublic void testDeleteEmployee() {try {employeeService.deleteEmployee(1);assertNull(employeeService.findEmployee(1));} catch (Exception e) {fail(e.getMessage());}}@Testpublic void testSaveOrUpdateEmployee() {try {employeeService.saveOrUpdateEmployee(1, "byron", "kiourtzoglou", "master software engineer");assertEquals(employeeService.findEmployee(1).getEmployeeName(), "byron");} catch (Exception e) {fail(e.getMessage());}}@Testpublic void stressTestSaveEmployee() {Callable<Integer> task = new Callable<Integer>() { public Integer call() throws Exception {int i;for(i = 3;i < 2048; i++) {employeeService.saveEmployee(i, "name-" + i, "surname-" + i, "developer-" + i);}return i;}};try {System.out.println("saveEmployee(...): " + new Benchmark(task, false, 2045));} catch (Exception e) {fail(e.getMessage());}assertNotNull(employeeService.findEmployee(1024));}@Testpublic void stressTestFindEmployee() {Callable<Integer> task = new Callable<Integer>() { public Integer call() { int i;for(i = 1;i < 2048; i++) {employeeService.findEmployee(i);}return i;}};try {System.out.println("findEmployee(...): " + new Benchmark(task, 2047));} catch (Exception e) {fail(e.getMessage());}}@Testpublic void stressTestFindAllEmployees() {Callable<List<EmployeeDTO>> task = new Callable<List<EmployeeDTO>>() { public List<EmployeeDTO> call() {return employeeService.findAllEmployees();}};try {System.out.println("findAllEmployees(): " + new Benchmark(task));} catch (Exception e) {fail(e.getMessage());}}@Testpublic void stressTestUpdateEmployee() {Callable<Integer> task = new Callable<Integer>() { public Integer call() throws Exception { int i;for(i=1;i<2048;i++) {employeeService.updateEmployee(i, "new_name-" + i, "new_surname-" + i, "new_developer-" + i);}return i;}};try {System.out.println("updateEmployee(...): " + new Benchmark(task, false, 2047));} catch (Exception e) {fail(e.getMessage());}assertEquals("new_name-1", employeeService.findEmployee(1).getEmployeeName());}@Testpublic void stressTestDeleteEmployee() {Callable<Integer> task = new Callable<Integer>() { public Integer call() throws Exception {int i;for(i = 1;i < 2048; i++) {employeeService.deleteEmployee(i);}return i;}};try {System.out.println("deleteEmployee(...): " + new Benchmark(task, false, 2047));} catch (Exception e) {fail(e.getMessage());}assertEquals(true, employeeService.findAllEmployees().isEmpty());}}

结果 …

下图显示了所有测试结果。纵轴表示每个测试的平均执行时间（以微秒（us）为单位），因此值越低越好。横轴表示测试类型。从上面的测试案例中可以看到，我们在数据库中插入了总数为2047个“员工”记录。对于检索测试用例（findEmployee（…）和findAllEmployees（…）），基准测试框架对每个测试用例进行了60次重复，以计算统计数据。所有其他测试用例仅执行一次。