Overview

The Felix OSGi framework is intended to be easily launchable and embeddable. For example, Felix avoids the use of system properties for configuration, since these are globals that can cause interference if multiple framework instances are created in the same VM. Felix is also implemented to multiplex singleton facilities, like the URL stream handler factory. The goal is to make it possible to use Felix in as many scenarios as possible; however, this is still just a goal. In other words, this is a work in progress and if any issues arise, it would be greatly appreciated if they are brought to the attention of the Felix community.

This document is divided into two main sections, one focusing on how to launch Felix and one focusing on how to embed Felix into a host application.

Launching Felix

High-level abstract description to go here.

Standard Felix Launcher

Sufficiently detailed description of the standard Felix launcher to go here.

Custom Felix Launcher

This section creates a bare-bones launcher to demonstrate the minimum requirements for creating an interactive launcher for the Felix framework. This example uses the standard Felix shell bundles for interactivity, but any other bundles could be used instead. For example, the shell service and telnet bundles could be used to lauch Felix and make it remotely accessible.

This example launcher has the following directory structure:

lib/
   org.apache.felix.framework-0.8.0-SNAPSHOT.jar
   org.osgi.core-0.8.0-SNAPSHOT.jar
bundle/
   org.apache.felix.shell-0.8.0-SNAPSHOT.jar
   org.apache.felix.shell.tui-0.8.0-SNAPSHOT.jar
src/
   example/
      Main.java

The lib/ directory contains the JAR files for the framework as well as the OSGi interfaces. The bundle/ directory contains the shell service and textual shell interface bundles that will be used for interacting with the framework instance. Note: If you do not launch Felix with interactive bundles, it will appear as if the framework instance hangs, but it is actually just sitting there waiting for someone to tell it to do something. The {[src/example/}} contains the following Main.java file, which is a very simplistic Felix launcher.

package example;

import java.util.Map;
import org.apache.felix.framework.Felix;
import org.apache.felix.framework.cache.BundleCache;
import org.apache.felix.framework.util.MutablePropertyResolverImpl;
import org.apache.felix.framework.util.StringMap;
import org.apache.felix.framework.util.FelixConstants;

public class Main
{
    private static Felix m_felix = null;

    public static void main(String[] argv) throws Exception
    {
        // Print welcome banner.
        System.out.println("\nWelcome to Felix.");
        System.out.println("=================\n");

        Map configMap = new StringMap(false);
        configMap.put(FelixConstants.FRAMEWORK_SYSTEMPACKAGES,
            "org.osgi.framework; version=1.3.0," +
            "org.osgi.service.packageadmin; version=1.2.0," +
            "org.osgi.service.startlevel; version=1.0.0," +
            "org.osgi.service.url; version=1.0.0");
        configMap.put(FelixConstants.AUTO_START_PROP + ".1",
            "file:bundle/org.apache.felix.shell-0.8.0-SNAPSHOT.jar " +
            "file:bundle/org.apache.felix.shell.tui-0.8.0-SNAPSHOT.jar");
        configMap.put(BundleCache.CACHE_PROFILE_DIR_PROP, "cache");

        try
        {
            // Now create an instance of the framework.
            m_felix = new Felix();
            m_felix.start(
                new MutablePropertyResolverImpl(configMap),
                null);
        }
        catch (Exception ex)
        {
            System.err.println("Could not create framework: " + ex);
            ex.printStackTrace();
            System.exit(-1);
        }
    }
}

Embedding Felix

to do

Host/Felix Interaction

to do

Providing Host Application Services

to do

Using Services Provided by Bundles

to do