Using HSQL in-memory database as JPA datasource

Question

I have an in-memory data source:

java.sql.Connection c = DriverManager.getConnection("jdbc:hsqldb:mem:testdb", "sa", "");            
emf = Persistence.createEntityManagerFactory("manager");

But now I'm stuck. I want to use it as a JPA data source in a J2SE application. I've scoured the entire web but all info is related to J2EE.

<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="manager">

        <jta-data-source>/*What to enter here?*/</jta-data-source>

        <properties>

            <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
            <property name="hibernate.hbm2ddl.auto" value="create-drop" />

        </properties>

    </persistence-unit>

</persistence>

Answer 1

/*What to enter here?*/

Well, nothing. In a Java SE environment, you'll have to use the built-in connection pool from your JPA provider and the setup looks like this:

<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="manager" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>com.acme.Foo</class>
    ...
    <properties>
      <property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
      <property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:mem:testdb"/>
      <property name="javax.persistence.jdbc.user" value="sa"/>
      <property name="javax.persistence.jdbc.password" value=""/>
      <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
    </properties>
  </persistence-unit>
</persistence>