Inject PersistenceContext from persistence.xml

Question

I'm trying to use the PersistenceContext annotation to inject an entity manager but I get the following exception.

 org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'Foo' available

Then I did some research and in every example there's a bean in the configuration class with the same information that I have in my persistence.xml.

Are we supposed to be able to inject the entitymanager with only the persistence-unit name?

Here's my code

@Component
public class UnitOfWork {
    @PersistenceContext(unitName="Foo")
    private EntityManager entityManager;
}

@Configuration
@ComponentScan("com.foo.package")
public class Config {
}

Persistence.xml in META-INF folder

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
             http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
  version="2.1">


    <persistence-unit name="Foo">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL57Dialect"/>
            <property name="hibernate.archive.autodetection" value="class" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/foo?useSSL=false" />
            <property name="hibernate.connection.username" value="foo"/>
            <property name="hibernate.connection.password" value="foo" />
        </properties>
    </persistence-unit>
</persistence>

Pom.xml

<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${org-springframework.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${org-springframework.version}</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-jpa -->
    <dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-jpa</artifactId>
        <version>2.0.7.RELEASE</version>
    </dependency>
            <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>5.0.6.RELEASE</version>
    </dependency>

Answer 1

You still need to define a LocalContainerEntityManagerFactory to have the EntityManagerFactory available in the application context. Without one that wouldn't work, the LocalContainerEntityManagerFactory will use the persistence.xml (when present) to configure itself.