SaveMultiDBHandler.java

package de.mukis.gemini.sample.rcp.handlers;

import java.lang.reflect.InvocationTargetException;

import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;

import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.ui.services.IServiceConstants;
import org.eclipse.gemini.ext.di.GeminiPersistenceUnit;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.widgets.Shell;

import de.mukis.gemini.sample.model.Person;
import de.mukis.gemini.sample.rcp.dao.PersonDAO;

/**
 * <p>
 * This POJO holds two database connections. One completely configured <br>
 * and the dynamic {@linkplain PersonDAO}.
 * </p>
 * 
 * <p>
 * The dao object won't be reinjected if some {@linkplain IEclipsePreferences}
 * change, <br>
 * so this is static.
 * </p>
 * 
 * 
 * @author muki
 * 
 */
public class SaveMultiDBHandler {

	@Inject
	@GeminiPersistenceUnit(unitName = "configured")
	EntityManagerFactory emf;

	@Execute
	public void execute(@Named(IServiceConstants.ACTIVE_SHELL) Shell shell, PersonDAO dao) throws InvocationTargetException,
			InterruptedException {

		try {
			// Via injected DAO
			Person person1 = new Person("Max", "Wild");
			dao.save(person1);
		} catch (Exception e) {
			MessageDialog.openError(shell, "Error persisting Person", "Something went wrong in the PersonDAO \n " + e.getMessage());
		}
		try {
			// Single EntityManager
			EntityManager em = emf.createEntityManager();
			em.getTransaction().begin();

			Person person2 = new Person("Bill", "Smith");
			em.persist(person2);
			em.getTransaction().commit();
			em.close();

			MessageDialog.openInformation(shell, "Person persisted",
					"Persisted person via injected DAO \n and via temporary EntityManager!");
		} catch (Exception e) {
			MessageDialog.openError(shell, "Error persisting Person", "Something went wrong with injected EMF \n " + e.getMessage());
		}

	}
}