Programming Open Service Gateways with Java Embedded Server™ Technology

Kirk Chen, a Staff Engineer at Sun Microsystems, has worked on design and implementation of the Java Embedded Server product since its inception. He has an M.S. in computer science from Stanford University. Li Gong is managing director of Sun Microsystems' Engineering and Research Institute in Beijing, China. Previously at Sun, he was engineering head of Java Security and Networking, Java Embedded Servers, and JXTA. He obtained B.S. and M.S. degrees from Tsinghua University, Beijing, and a Ph.D. from the University of Cambridge. He is associate editor-in-chief of IEEE Internet Computing.

Preface.


Acknowledgments.


1. Introduction.


The Internet and the Networked Home.



The Service Gateway.



Challenges.



A Multitude of Competing Solutions.



A New Application Environment.



Java Embedded Server Technology.



The Open Services Gateway Initiative.



Operational Model.



2. Getting Started.


Setting Up the Java Embedded Server Software.



The "Home, Sweet Home" Bundle.



Create the Directory.



Define the Manifest.



Write an Activator.



Compile the Activator Class.



Pack Up.



Running the Bundle.



Getting Help.



The Cache Directory.



The Bundle Base URL.



Brief Summary of the Major Commands.



3. Architecture and Basic Concepts.


Motivation.



Architecture.



Service.



Bundle.



A Bundle Is a Packaging Vehicle.



A Bundle Is a Functional Module.



The "Hooks" to the Framework.



The Framework.



Cooperation among Bundles and Services.



Exporting and Importing Packages.



Registering and Obtaining Services.



Package versus Service Dependency.



Life within the Framework.



Installing a Bundle.



Starting the Bundle.



Importing Packages and Getting Services.



Handling the Dynamic Service Dependency.



Updating a Bundle.



Stopping and Uninstalling a Bundle.



The Component-based Model.



Forget CLASSPATH.



4. Developing Bundles.


Writing Service Bundles.



Design the Service Interface.



Implement the Service.



Register the Service in the Activator.



Define the Manifest Headers.



Create the Bundle.



Same Service Interface, Different Implementations.



Retrieving Resources from within the Bundle.



Obtaining and Calling Registered Services.



Interbundle Dependency and Class Loading Issues.



Service Use Count.



Compiling Client Bundles.



Service Factory.



Producing a Customized Service for Each Client Bundle.



Service Cache.



Customization for Getting and Releasing Service.



Relevant org.osgi.framework APIs.



BundleContext Interface.



ServiceReference Interface.



ServiceRegistration Interface.



Library Bundles.



Advanced Examples.



A Mailer.



A Line Printer Daemon Print Service.



Writing Bundles That Contain Native Code.



Common Mistakes.



Activator.



Manifest.



Creating a JAR File.



5. Cooperation among Service Bundles.


Event Handling.



Bundle State and Service Registration.



Synchronous and Asynchronous Events.



Dealing with Service Unregistration.



Don't Start without the Service.



Discovering Stale Service.



Carrying On without the Service.



Picking an Alternative.



Cascading Service Registration.



Refusing Service.



Cooperation with Asynchronous Events.



6. Design Patterns and Pitfalls.


Designing the Service.



Separating Service Interface and Implementation.



Challenges in Designing a Service Interface.



Approaching an Interface Design.



The Social Aspect.



Designing Library Bundles.



Delegation and Callback.



Leveraging the Service Registry.



Threading.



Preventing Runaway Threads.



Writing a Multithread Server Bundle.



Using a Thread Pool.



Managing Object Allocation.



Nullify References After Use.



Managing References among Bundles.



7. Standard Services.


The Log Service.



Using LogService to Write Logs.



Using LogReaderService to Get Logs.



Performing Persistent Logging.



The HTTP Service.



The Standard HttpService API.



Performing Basic Authentication.



The Extended HTTP Service.



8. Device Access.


Introduction.



The Software Stack in Device Access.



What Device Access Is Not.



Motivation.



Cast of Characters.



Device Service.



Driver Services.



Driver Locator.



Device Manager.



Writing DA Services.



The Base Driver.



Device Detection.



Device Refinement.



The Reconfiguration Process.



Putting It Together.



9. Permission-based Security and Administration.


Permission-based Security inside the Java 2 Platform.



Code Source.



Permission.



Policy.



Granting Permissions to Classes.



Security Manager.



OSGi Permissions.



AdminPermission.



ServicePermission.



PackagePermission.



Permission Required by the Framework APIs.



Enabling Security.



Setting Up a Policy.



Running with Security Enabled.



Using Permissions in Your Service.



Checking Permissions.



Performing Privileged Actions.



Creating Your Own Permission Types.



Administration.



Resolving Bundles Dynamically.



Relevant APIs.



10. Future Directions.


Removing Phantom Bundles.



Dynamic Permissions.



Preferences.



User Administration.



Configuration Management.



What's Next.



Appendix A. Code Examples.


Chapter 4--Developing Bundles.



The LPD Print Service.



Chapter 8--Device Access.



Serial Service and Driver Locator.



Driver Service and Modem Service.



Web Interface to the Serial Ports.



Chapter 9--Permission-based Security and Administration.



Parameter Services.



Parameter Configuration Servlet.



Facilitator.



Appenidix B. OSGi Service Gateway Specification.


org.osgi.framework.



AdminPermission.



Bundle.



BundleActivator.



BundleContext.



BundleEvent.



BundleException.



BundleListener.



Configurable.



FrameworkEvent.



FrameworkListener.



InvalidSyntaxException.



PackagePermission.



ServiceEvent.



ServiceFactory.



ServiceListener.



ServicePermission.



ServiceReference.



ServiceRegistration.



org.osgi.service.device.



Device.



Driver.



DriverLocator.



org.osgi.service.http.



HttpContext.



HttpService.



NamespaceException.



org.osgi.service.log.



LogEntry.



LogListener.



LogReaderService.



LogService.



Bibliography.


Index. 0201711028T08142001