Service Activator Toolkit

Step 2: Updating the Hotdog Vendor Bundle to Export a Service with Registered Properties

In this step the Hotdog Vendor bundle is updated to export an implementation of the VendorService with a property that describes its spiciness.

In the Package Explorer find the org.eclipse.soda.sat.tutorial.vendor.hotdog project.

Find the bundle activator and update it as follows. The updates are highlighted in bold.

package org.eclipse.soda.sat.tutorial.vendor.hotdog.bundle;

import java.util.Dictionary;
import java.util.Hashtable;

import org.eclipse.soda.sat.core.framework.BaseBundleActivator;
import org.eclipse.soda.sat.core.util.LogUtility;
import org.eclipse.soda.sat.tutorial.vendor.hotdog.HotdogVendor;
import org.eclipse.soda.sat.tutorial.vendor.service.VendorService;

public class Activator extends BaseBundleActivator {
  protected void activate() {
    LogUtility.logInfo("The Hotdog Vendor bundle has been activated");  //$NON-NLS-1$
    addExportedVendorService();
  }

  private void addExportedVendorService() {
    VendorService service = new HotdogVendor();
    Dictionary properties = new Hashtable(11);
    properties.put(VendorService.SPICINESS_PROPERTY, new Integer(10));
    addExportedService(VendorService.SERVICE_NAME, service, properties);
  }

  protected void deactivate() {
    LogUtility.logInfo("The Hotdog Vendor bundle has been deactivated");  //$NON-NLS-1$
  }
}

As you can see, the addExportedVendorService() methods has been updated to create a Dictionary of properties that is passed to the addExportedService(String, Object, Dictionary) method when the VendorService is exported. In this case the single property key VendorService.SPICINESS_PROPERTY is registered with the value new Integer(10).
Defining a property key such as SPICINESS_PROPERTY in the service interface, in this case VendorService, is a useful technique since it defines a common property key that can be used by all bundles that implement the interface and register a service.
Notice that unlike System.setProperty(String, String), registered service properties are instances of Object not just a String.

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