GlobalsManager.java

package org.wahlzeit.model;

import com.googlecode.objectify.ObjectifyService;
import com.googlecode.objectify.Work;
import org.wahlzeit.services.ObjectManager;
import org.wahlzeit.servlets.AbstractServlet;

import java.util.logging.Logger;

import static org.wahlzeit.services.OfyService.ofy;

/**
 * Manager that cares about the global variables. It is used from the outside by the following two methods:
 *
 * @see #loadGlobals()
 * @see #saveGlobals()
 * 
 * @review
 */
public class GlobalsManager extends ObjectManager {

	private static final Logger log = Logger.getLogger(GlobalsManager.class.getName());
	/**
	 *
	 */
	private static GlobalsManager instance = new GlobalsManager();

	/**
	 * @methodtype command Loads all global variables and stores them in their corresponding classes.
	 */
	public void loadGlobals() {
		initGlobals();
		Globals globals = ObjectifyService.run(new Work<Globals>() {
			@Override
			public Globals run() {
				return readObject(Globals.class, Globals.DEAULT_ID);
			}
		});
		log.info(globals.asString());

		UserManager.getInstance().setLastClientId(globals.getLastUserId());
		PhotoId.setCurrentIdFromInt(globals.getLastPhotoId());
		Case.setLastCaseId(new CaseId(globals.getLastCaseId()));
		AbstractServlet.setLastSessionId(globals.getLastSessionId());
	}

	/**
	 * @methodtype wrapper
	 */
	private void initGlobals() {
		if (!GlobalsManager.getInstance().hasGlobals()) {
			createDefaultGlobals();
		}
	}

	/**
	 * @methodtype boolean querry
	 */
	private boolean hasGlobals() {
		return ObjectifyService.run(new Work<Boolean>() {
			@Override
			public Boolean run() {
				return ofy().load().type(Globals.class).first().now() != null;
			}
		});
	}

	/**
	 * @methodtype get
	 */
	public static GlobalsManager getInstance() {
		return instance;
	}

	/**
	 * @methodtype command
	 */
	private void createDefaultGlobals() {
		ObjectifyService.run(new Work<Boolean>() {
			@Override
			public Boolean run() {
				Globals globals = new Globals();
				globals.setLastUserId(Globals.DEAULT_ID);
				globals.setLastPhotoId(0);
				globals.setLastCaseId(0);
				globals.setLastSessionId(0);
				ofy().save().entity(globals).now();
				return null;
			}
		});
	}

	/**
	 * @methodtype command Saves all global variables.
	 */
	public synchronized void saveGlobals() {
		final Globals globals = new Globals();
		globals.setLastUserId(UserManager.getInstance().getLastClientId());
		globals.setLastPhotoId(PhotoId.getCurrentIdAsInt());
		globals.setLastCaseId(Case.getLastCaseId().asInt());
		globals.setLastSessionId(AbstractServlet.getLastSessionId());
		log.info(globals.asString());

		ObjectifyService.run(new Work<Void>() {
			@Override
			public Void run() {
				writeObject(globals);
				return null;
			}
		});
	}
}