Importing "outside" java class in embedeed OSGi equinox framework - osgi

Question

I have to embed Eclipse/Equinox OSGi Framework to existing application.
I found this tutorial http://njbartlett.name/2011/03/07/embedding-osgi.html and try to use FRAMEWORK_SYSTEMPACKAGES_EXTRA Constans.
So I try export a simple java class into running framework by system bundle, but I receive following error from my activator bundle
Exception in thread "main" org.osgi.framework.BundleException: The activator com.bundleactivator.Activator for bundle com.bundleactivator is invalid
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:156)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:751)
at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:370)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:284)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:276)
at RunNewEquinoxOsgi.main(RunNewEquinoxOsgi.java:74)
Caused by: java.lang.Error: Unresolved compilation problem:
The import example cannot be resolved
at com.bundleactivator.Activator.<init>(Activator.java:8)
at java.lang.J9VMInternals.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1505)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadBundleActivator(AbstractBundle.java:151)
... 5 more
Exceptions are thrown in the place where I import the example.osgi package from system bundle in the activator
import example.osgi.Example;
I launch equinox by FrameworkFactory in other java class
import java.util.HashMap;
import java.util.Map;
import java.util.ServiceLoader;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.launch.Framework;
import org.osgi.framework.launch.FrameworkFactory;
import example.osgi.*;
FrameworkFactory frameworkFactory = ServiceLoader.load(FrameworkFactory.class).iterator().next();
Map<String, String> config = new HashMap<String, String>();
config.put(Constants.FRAMEWORK_SYSTEMPACKAGES_EXTRA,
"example.osgi;version=\"1.0.0\"");
try {
framework.start();
System.out.println("Framework start");
} catch (BundleException e) {
e.printStackTrace();
}
BundleContext ctx = framework.getBundleContext();
Bundle b3 = ctx.installBundle("file:C:\\equinoxtest\\ds.jar");
System.out.println(b3.getBundleId() + " installed");
Bundle b4 = ctx.installBundle("file:C:\\equinoxtest\\services.jar");
System.out.println(b4.getBundleId() + " installed");
Bundle b5 = ctx.installBundle("file:C:\\equinoxtest\\util.jar");
System.out.println(b5.getBundleId() + " installed");
Bundle b6 = ctx.installBundle("file:C:\\equinoxtest\\service.jar");
System.out.println(b6.getBundleId() + " installed");
Bundle b7 = ctx.installBundle("file:C:\\equinoxtest\\rule1.jar");
System.out.println(b7.getBundleId() + " installed");
Bundle b8 = ctx.installBundle("file:C:\\equinoxtest\\rule2.jar");
System.out.println(b8.getBundleId() + " installed");
Bundle b9 = ctx.installBundle("file:C:\\equinoxtest\\rule3.jar");
System.out.println(b9.getBundleId() + " installed");
Bundle b10 = ctx.installBundle("file:C:\\equinoxtest\\activator.jar");
System.out.println(b10.getBundleId() + " installed");
b3.start();
b4.start();
b5.start();
b6.start();
b7.start();
b8.start();
b9.start();
b10.start(); // here i start the activator
This is the manifest of activator class
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: BundleActivator
Bundle-SymbolicName: com.bundleactivator
Bundle-Version: 1.0.0.qualifier
Bundle-Activator: com.bundleactivator.Activator
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
Import-Package: com.bundleservice,
example.osgi;version="1.0.0";resolution:=optional,
org.osgi.framework;version="1.3.0",
org.osgi.util.tracker;version="1.4.0"
Bundle-ActivationPolicy: lazy
Export-Package: com.bundleactivator
In the OSGi console i see this package (example.osgi) in system bundle exports, but the importing class(activator) throw Exception. What else should i do?
>osgi packages 0
...
example.osgi; version="1.0.0"<org.eclipse.osgi_3.6.2.R36x_v20110210 [0]>

Answer 1

This error:
java.lang.Error: Unresolved compilation problem
indicates that you are building your code with Eclipse, but there are compilation errors. You need to make your code compile before you run it.
Background info: Eclipse does not use the javac command for compilation, it has a built-in Java compiler known as ECJ. This compiler is designed for incremental use inside the IDE, and it tries its best to keep going even in the presence of errors. So it will still produce a valid .class file, however if you actually try to run something that touches the class(es) with errors in, then you get the above runtime error. In contrast, javac simply stops when it hits a compilation error and will not produce a .class file that you can run.