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package org.apache.olingo.odata2.processor.api.jpa;
import org.apache.olingo.odata2.api.ODataService;
import org.apache.olingo.odata2.api.ODataServiceFactory;
import org.apache.olingo.odata2.api.edm.provider.EdmProvider;
import org.apache.olingo.odata2.api.exception.ODataException;
import org.apache.olingo.odata2.api.processor.ODataContext;
import org.apache.olingo.odata2.api.processor.ODataSingleProcessor;
import org.apache.olingo.odata2.processor.api.jpa.exception.ODataJPARuntimeException;
import org.apache.olingo.odata2.processor.api.jpa.factory.ODataJPAAccessFactory;
import org.apache.olingo.odata2.processor.api.jpa.factory.ODataJPAFactory;
/**
* <p>
* Extend this factory class and create own instance of {@link org.apache.olingo.odata2.api.ODataService} that
* transforms Java Persistence
* Models into an OData Service. The factory class instantiates instances of
* type {@link org.apache.olingo.odata2.api.edm.provider.EdmProvider} and
* {@link org.apache.olingo.odata2.api.processor.ODataSingleProcessor}. The OData
* JPA Processor library provides a default implementation for EdmProvider and
* OData Single Processor.
* </p>
* <p>
* The factory implementation is passed as servlet init parameter to a JAX-RS
* runtime which will instantiate a {@link org.apache.olingo.odata2.api.ODataService} implementation using this factory.
* </p>
*
* <p>
* <b>Mandatory:</b> Implement the abstract method initializeODataJPAContext. Fill
* {@link org.apache.olingo.odata2.processor.api.jpa.ODataJPAContext} with context
* values.
* </p>
*
* <b>Sample Configuration:</b>
*
* <pre> {@code
* <servlet>
* <servlet-name>ReferenceScenarioServlet</servlet-name>
* <servlet-class>org.apache.cxf.jaxrs.servlet.CXFNonSpringJaxrsServlet</servlet-class>
* <init-param>
* <param-name>javax.ws.rs.Application</param-name>
* <param-value>org.apache.olingo.odata2.core.rest.ODataApplication</param-value>
* </init-param>
* <init-param>
* <param-name>org.apache.olingo.odata2.processor.factory</param-name>
* <param-value>foo.bar.sample.processor.SampleProcessorFactory</param-value>
* </init-param>
* <init-param>
* <param-name>org.apache.olingo.odata2.path.split</param-name>
* <param-value>2</param-value>
* </init-param>
* <load-on-startup>1</load-on-startup>
* </servlet>
* } </pre>
*/
public abstract class ODataJPAServiceFactory extends ODataServiceFactory {
private ODataJPAContext oDataJPAContext;
private ODataContext oDataContext;
/**
* Creates an OData Service based on the values set in
* {@link org.apache.olingo.odata2.processor.api.jpa.ODataJPAContext} and
* {@link org.apache.olingo.odata2.api.processor.ODataContext}.
*/
@Override
public final ODataService createService(final ODataContext ctx) throws ODataException {
oDataContext = ctx;
// Initialize OData JPA Context
oDataJPAContext = initializeODataJPAContext();
validatePreConditions();
ODataJPAFactory factory = ODataJPAFactory.createFactory();
ODataJPAAccessFactory accessFactory = factory.getODataJPAAccessFactory();
// OData JPA Processor
if (oDataJPAContext.getODataContext() == null) {
oDataJPAContext.setODataContext(ctx);
}
ODataSingleProcessor odataJPAProcessor = accessFactory.createODataProcessor(oDataJPAContext);
// OData Entity Data Model Provider based on JPA
EdmProvider edmProvider = accessFactory.createJPAEdmProvider(oDataJPAContext);
return createODataSingleProcessorService(edmProvider, odataJPAProcessor);
}
private void validatePreConditions() throws ODataJPARuntimeException {
if (oDataJPAContext.getEntityManagerFactory() == null) {
throw ODataJPARuntimeException.throwException(ODataJPARuntimeException.ENTITY_MANAGER_NOT_INITIALIZED, null);
}
}
/**
* Implement this method and initialize OData JPA Context. It is mandatory
* to set an instance of type {@link javax.persistence.EntityManagerFactory} into the context. An exception of type
* {@link org.apache.olingo.odata2.processor.api.jpa.exception.ODataJPARuntimeException} is thrown if
* EntityManagerFactory is not initialized. <br>
* <br>
* <b>Sample Code:</b> <code>
* <p>public class JPAReferenceServiceFactory extends ODataJPAServiceFactory{</p>
*
* <blockquote>private static final String PUNIT_NAME = "punit";
* <br>
* public ODataJPAContext initializeODataJPAContext() {
* <blockquote>ODataJPAContext oDataJPAContext = this.getODataJPAContext();
* <br>
* EntityManagerFactory emf = Persistence.createEntityManagerFactory(PUNIT_NAME);
* <br>
* oDataJPAContext.setEntityManagerFactory(emf);
* oDataJPAContext.setPersistenceUnitName(PUNIT_NAME);
* <br> return oDataJPAContext;</blockquote>
* }</blockquote>
* } </code>
* <p>
*
* @return an instance of type {@link org.apache.olingo.odata2.processor.api.jpa.ODataJPAContext}
* @throws ODataJPARuntimeException
*/
public abstract ODataJPAContext initializeODataJPAContext() throws ODataJPARuntimeException;
/**
* @return an instance of type {@link ODataJPAContext}
* @throws ODataJPARuntimeException
*/
public final ODataJPAContext getODataJPAContext() throws ODataJPARuntimeException {
if (oDataJPAContext == null) {
oDataJPAContext = ODataJPAFactory.createFactory().getODataJPAAccessFactory().createODataJPAContext();
}
if (oDataContext != null) {
oDataJPAContext.setODataContext(oDataContext);
}
return oDataJPAContext;
}
}