如何在另一个项目中使用Eclipse OSGi Java插件？

Question

This is all so new for me and a bit complex. I created a plug-in project in Eclipse with a standard OSGi framework. The aim is to connect to H2 DB with this bundle. Here is the Activator.java: package dbservice;

import java.sql.Connection;
import java.sql.DriverManager;

import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;

public class Activator implements BundleActivator {

private static BundleContext context;
private Connection conn=null;

static BundleContext getContext() {
    return context;
}


public void start(BundleContext bundleContext) throws Exception {
    Activator.context = bundleContext;
    Class.forName("org.h2.Driver");
    conn = DriverManager.getConnection("jdbc:h2:~/test","sa","123456");
    System.out.print("Connection opened...");
}

public void stop(BundleContext bundleContext) throws Exception {
    Activator.context = null;
    conn.close();
    System.out.print("Connection closed...");
}

}

I run this project within OSGi framework. It is working there. But my question is, how do I use this bundle in another project?

Answer 1

The question is what you really want to provide to other bundles. If you want to provide a generic way to access a database then you can provide a DataSource. In this case I recommend to use pax-jdbc-config as it does all the heavy lifting for you.

Another options is Aries transactioncontrol which is even a bit easier to use but makes your user code depend on the transaction control API.

If you want to provide something higher level then a service is the best choice. Create an interface for your service and implement the interface in your bundle. Then simply export the object as an OSGi service. Other bundles can then pick up the service. I recommend to use declarative services for offering and consuming services. See this example .