No Persistence provider for EntityManager named

Question

I have my persistence.xml with the same name using TopLink under the META-INF directory. Then, I have my code calling it with:

Answer 1

Mine got resolved by adding info in persistence.xml e.g. <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> and then making sure you have the library on classpath e.g. in Maven add dependency like

<dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>eclipselink</artifactId>
  <version>2.5.0</version>
</dependency>

Answer 2

There is another point: If you face this problem within an Eclipse RCP environment, you might have to change the Factory generation from Persistence.createEntityManagerFactory to new PersistenceProvider().createEntityManagerFactory

see ECF for a detailed discussion on this.

Answer 3

If you are using Eclipse make sure that exclusion pattern does not remove your persistence.xml from source folders on build path.

1. Go to Properties -> Java Build Path -> Source tab
2. Check your exclusion pattern which is located at
   MyProject/src/main/java -> Excluded: <your_pattern>
   tree node
3. Optionally, set it to Excluded: (None) by selecting the node and clicking Edit... button on the left.

Answer 4

Had the same issue, but this actually worked for me :

mvn install -e  -Dmaven.repo.local=$WORKSPACE/.repository.

NB : The maven command above will reinstall all your project dependencies from scratch. Your console will be loaded with verbose logs due to the network request maven is making.

Answer 5

I just copied the META-INF into src and worked!

Answer 6

Verify the peristent unit name

<persistence-unit name="com.myapp.model.jpa"
    transaction-type="RESOURCE_LOCAL">    
public static final String PERSISTENCE_UNIT_NAME = "com.myapp.model.jpa";
Persistence.createEntityManagerFactory(**PERSISTENCE_UNIT_NAME**);