Writing Local Service Classes

The heart of your service is its -LocalServiceImpl class, where you put core business logic for working with your model. Throughout this chapter, you’ve been constructing services for the Nose-ster Event Listing example portlet project. Start with your services by examining the initial service classes Service Builder generated for it.

Note that Service Builder created an EventLocalService class which is the interface for the local service. It contains the signatures of every method in EventLocalServiceBaseImpl and EventLocalServiceImpl. EventLocalServiceBaseImpl contains a few automatically generated methods providing common functionality. Since the EventLocalService class is generated, you should never modify it. If you do, your changes will be overwritten the next time you run Service Builder. Instead, all custom code should be placed in EventLocalServiceImpl.

Open the EventLocalServiceImpl.java file in your /docroot/WEB-INF/src/com/nosester/portlet/eventlisting/service/impl/ folder.

Add the following database interaction methods to the EventLocalServiceImpl class:

public Event addEvent(
        long userId, long groupId, String name, String description,
        int month, int day, int year, int hour, int minute, long locationId,
        ServiceContext serviceContext)
    throws PortalException, SystemException {

    User user = userPersistence.findByPrimaryKey(userId);

    Date now = new Date();

    long eventId = counterLocalService.increment(Event.class.getName());

    Event event = eventPersistence.create(eventId);

    event.setName(name);
    event.setDescription(description);

    Calendar dateCal = CalendarFactoryUtil.getCalendar(
        user.getTimeZone());
    dateCal.set(year, month, day, hour, minute);
    Date date = dateCal.getTime();
    event.setDate(date);

    event.setLocationId(locationId);

    event.setGroupId(groupId);
    event.setCompanyId(user.getCompanyId());
    event.setUserId(user.getUserId());
    event.setCreateDate(serviceContext.getCreateDate(now));
    event.setModifiedDate(serviceContext.getModifiedDate(now));

    super.addEvent(event);

    // Resources

    resourceLocalService.addResources(
        event.getCompanyId(), event.getGroupId(), event.getUserId(),
        Event.class.getName(), event.getEventId(), false,
        true, true);

    return event;
}

public Event deleteEvent(Event event) throws SystemException {

    return eventPersistence.remove(event);
}

public Event deleteEvent(long eventId)
    throws PortalException, SystemException {

    Event event = eventPersistence.findByPrimaryKey(eventId);

    return deleteEvent(event);
}

public Event getEvent(long eventId)
    throws SystemException, PortalException {

    return eventPersistence.findByPrimaryKey(eventId);
}

public List<Event> getEventsByGroupId(long groupId) throws SystemException {

    return eventPersistence.findByGroupId(groupId);
}

public List<Event> getEventsByGroupId(long groupId, int start, int end)
    throws SystemException {

    return eventPersistence.findByGroupId(groupId, start, end);
}

public int getEventsCountByGroupId(long groupId) throws SystemException {

    return eventPersistence.countByGroupId(groupId);
}

public Event updateEvent(
        long userId, long eventId, String name, String description,
        int month, int day, int year, int hour, int minute,
        long locationId, ServiceContext serviceContext)
    throws PortalException, SystemException {

    User user = userPersistence.findByPrimaryKey(userId);

    Date now = new Date();

    Event event = EventLocalServiceUtil.fetchEvent(eventId);

    event.setModifiedDate(serviceContext.getModifiedDate(now));
    event.setName(name);
    event.setDescription(description);

    Calendar dateCal = CalendarFactoryUtil.getCalendar(
        user.getTimeZone());
    dateCal.set(year, month, day, hour, minute);
    Date date = dateCal.getTime();
    event.setDate(date);

    event.setLocationId(locationId);

    super.updateEvent(event);

    return event;
}	

Remember to import the required classes. These include the following:

com.nosester.portlet.eventlisting.model.Event
com.liferay.portal.kernel.exception.PortalException
com.liferay.portal.kernel.exception.SystemException
com.liferay.portal.model.User
com.liferay.portal.service.ServiceContext
java.util.Date
java.util.List

In order to add an Event to the database, you need an ID for the Event. Liferay provides a counter service which you call to obtain a unique ID for each new Event entity. It’s possible to use the increment method of Liferay’s CounterLocalServiceUtil class but Service Builder already makes a CounterLocalService instance available to EventLocalServiceBaseImpl via Spring by dependency injection. Since your EventLocalServiceImpl class extends EventLocalServiceBaseImpl, you can access this CounterLocalService instance. See EventLocalServiceBaseImpl for a list of all the beans that Spring makes available for use. These include the following beans:

• eventLocalService
• eventPersistence
• locationLocalService
• locationPersistence
• counterLocalService
• resourceLocalService
• resourceService
• resourcePersistence
• userLocalService
• userService
• userPersistence

It’s a best practice to use the injected class’s increment method rather than calling Liferay’s CounterLocalService’s increment method since using the injected class does not require an extra database transaction. Calling Liferay’s CounterLocalServiceUtil class, on the other hand, does require an extra database transaction.

long eventId = counterLocalService.increment(Event.class.getName());

We use the generated eventId as the ID for the new Event:

Event event = eventPersistence.create(eventId);

eventPersistence is one of the Spring beans injected into EventLocalServiceBaseImpl by Service Builder.

Next, we set the attribute fields that we specified for the Event. First, we set the name and description of the Event. Then we use the date and time values to construct the Event’s date. Lastly, we associate a location with the Event.

Then we assign values to the audit fields. First, we set the group, or scope, of the entity. In this case the group is the site. Then we set the company and user. The company represents the portal instance. We set the createDate and modifiedDate of our Event to the current time. After that, we call the generated addEvent method of EventLocalServiceBaseImpl with our Event. Lastly, we add the Event as a resource so that we can apply permissions to it later. We’ll cover the details of adding resources in Chapter 12.

Before you can use any custom methods that you added to EventLocalServiceImpl class, you must add their signatures to the EventLocalService interface by running Service Builder again.

Using Developer Studio: As we did before, open your service.xml file and make sure you are in the Overview mode. Then, select Build Services.

Using the terminal: Navigate to the root directory of your portlet in the terminal and run:

ant build-service

Service Builder looks through EventLocalServiceImpl and automatically copies the signatures of each method into the interface. You can now add a new Event to the database by invoking the static addEvent method that Service Builder generated in the EventLocalServiceUtil utility class. In addition to all the Java classes, Service Builder also generates a service.properties file which will be covered later. Next, let’s call our newly implemented local service.