How to configure OpenJPA using Spring 3 with Annotation-Based Transactions

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<context:component-scan base-package="com.example" />
	<context:annotation-config/>

	<!-- ******************************************************************** -->
	<!-- Include context files from different layers -->
	<!-- ******************************************************************** -->
	<import resource="security-context.xml" />
	<import resource="service-context.xml" />
	<import resource="dao-context.xml" />
	
</beans>

CustomerDaoImpl.java

package com.sample.dao.impl

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.Query;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

@Component("CustomerDao")
public class CustomerDaoImpl {

	@PersistenceContext
	private EntityManager em;

	public Customer getCustomerByName(String customerName) {
		Query query = getEm().createQuery("SELECT c FROM Customer c WHERE c.name = ?1");
		query.setParameter(1, customerName);
		List<Customer> results = query.getResultList();
		if (results.size() > 0) {
			return results.get(0);
		}
		return null;
	}

	protected EntityManager getEm() {
		return em;
	}
}

dao-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://www.springframework.org/schema/beans"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
		http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
		http://www.springframework.org/schema/tx
		http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

	<!-- ******************************************************************** -->
	<!-- Mark bean transactions as annotation driven -->
	<!-- ******************************************************************** -->
	<tx:annotation-driven transaction-manager="transactionManager" />

	<!-- ******************************************************************** -->
	<!-- PropertyConfigurer for the DAO -->
	<!-- ******************************************************************** -->
	<bean id="propertyConfigurer"
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="location" value="classpath:db.properties" />
	</bean>

	<!-- ******************************************************************** -->
	<!-- Setup the transaction manager -->
	<!-- ******************************************************************** -->
	<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
		<property name="entityManagerFactory" ref="entityManagerFactory" />
	</bean>

	<!-- ******************************************************************** -->
	<!-- Setup each data source -->
	<!-- ******************************************************************** -->
	<bean id="dataSource"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName" value="${connection.driver_class}" />
		<property name="url" value="${connection.url}" />
		<property name="username" value="${connection.username}" />
		<property name="password" value="${connection.password}" />
	</bean>

	<!-- ******************************************************************** -->
	<!-- Setup each persistence unit -->
	<!-- ******************************************************************** -->

	<!-- Configure a JPA vendor adapter -->
	<bean id="openJpaVendorAdapter" class="org.springframework.orm.jpa.vendor.OpenJpaVendorAdapter">
		<property name="showSql" value="${connection.show_sql}" />
		<property name="generateDdl" value="${connection.generateDdl}" />
		<property name="databasePlatform" value="${connection.dialect}" />
	</bean>

	<!-- EntityManager Factory that brings together the persistence unit, datasource, 
		and JPA Vendor -->
	<bean id="entityManagerFactory"
		class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
		<property name="dataSource" ref="dataSource" />
		<property name="jpaVendorAdapter" ref="openJpaVendorAdapter" />
		<property name="persistenceUnitName" value="scrum-board-persistence-unit" />
	</bean>
	
	<bean id="sharedEntityManager" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
		<property name="entityManagerFactory" ref="entityManagerFactory"/>
	</bean>
</beans>

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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">
	
	<persistence-unit name="entityManagerFactory" transaction-type="RESOURCE_LOCAL" >
		<description>generated-persistence-unit</description>
		<provider>org.apache.renamed.openjpa.persistence.PersistenceProviderImpl</provider>
    		<class>com.example.Class1</class>
     		<class>com.example.Class2</class>
	</persistence-unit>
	
</persistence>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>group.name</groupId>
	<artifactId>artifact</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>
	<name>Project Name</name>
	<dependencies>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<scope>provided</scope>
			<version>3.0.1</version>
		</dependency>
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.16</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>3.0.5.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-web</artifactId>
			<version>3.0.5.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-orm</artifactId>
			<version>3.0.5.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-tx</artifactId>
			<version>3.0.5.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.4</version>
		</dependency>
		<dependency>
 			<groupId>org.apache.openjpa</groupId>
 			<artifactId>openjpa</artifactId>
 			<version>2.2.0</version>
		</dependency>
		<dependency>
			<groupId>com.oracle.jdbc</groupId>
			<artifactId>ojdbc5</artifactId>
			<version>11.2.0.1.0</version>
		</dependency>
		<dependency>
			<groupId>org.eclipse.persistence</groupId>
			<artifactId>javax.persistence</artifactId>
			<version>2.0.0</version>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>1.6</source>
					<target>1.6</target>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.codehaus.mojo</groupId>
				<artifactId>openjpa-maven-plugin</artifactId>
				<version>1.2</version>
				<configuration>
					<connectionDriverName>oracle.jdbc.driver.OracleDriver</connectionDriverName>
					<includes>${basedir}/target/classes/**/*.class</includes>
					<addDefaultConstructor>true</addDefaultConstructor>
					<enforcePropertyRestrictions>true</enforcePropertyRestrictions>
				</configuration>
				<executions>
					<execution>
						<id>enhancer</id>
						<phase>process-classes</phase>
						<goals>
							<goal>enhance</goal>
						</goals>
					</execution>
				</executions>
				<dependencies>
					<dependency>
						<groupId>org.apache.openjpa</groupId>
						<artifactId>openjpa</artifactId>
 						<version>2.2.0</version>
					</dependency>
				</dependencies>
			</plugin>
		</plugins>
	</build>
</project>

This is the only sample code I could find to integrate spring3 with OpenJPA. However I kept getting "[ERROR] Failed to execute goal org.codehaus.mojo:openjpa-maven-plugin:1.2:enhance (enhancer) on project spring-osgi-test: Execution enhancer of goal org.codehaus.mojo:openjpa-maven-plugin:1.2:enhance failed: MetaDataFactory could not be configured (conf.newMetaDataFactoryInstance() returned null)."

Turns out org.apache.renamed.openjpa.persistence.PersistenceProviderImpl is incorrect.
It should be org.apache.openjpa.persistence.PersistenceProviderImpl

I reduced the dependencies to the following...

       <dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>3.1.0.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>3.1.0.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.testng</groupId>
        <artifactId>testng</artifactId>
        <version>6.3.1</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.openjpa</groupId>
        <artifactId>openjpa</artifactId>
        <version>2.2.0</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.18</version>
    </dependency>

    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>1.0.0.GA</version>
    </dependency>
</dependencies>

could you please share your db.properties file

could you please share your db.properties file? thanks

What should db.properties look like?

db.properties should just hold the constants regarding to DB. it should depend on your own DB setup.

<!-- ******************************************************************** -->
<bean id="dataSource"
	class="org.springframework.jdbc.datasource.DriverManagerDataSource">
	<property name="driverClassName" value="${connection.driver_class}" />
	<property name="url" value="${connection.url}" />
	<property name="username" value="${connection.username}" />
	<property name="password" value="${connection.password}" />
</bean>

<!-- ******************************************************************** -->
<!-- Setup each persistence unit -->
<!-- ******************************************************************** -->

<!-- Configure a JPA vendor adapter -->
<bean id="openJpaVendorAdapter" class="org.springframework.orm.jpa.vendor.OpenJpaVendorAdapter">
	<property name="showSql" value="${connection.show_sql}" />
	<property name="generateDdl" value="${connection.generateDdl}" />
	<property name="databasePlatform" value="${connection.dialect}" />
</bean>

these properties should come from there