The custom SingletonProvider using the current class context

CurrentBundleSingletonProvider.java

package org.jboss.weld.environment.osgi.integration;

import java.util.Hashtable;
import java.util.Map;
import org.jboss.weld.bean.proxy.ProxyMethodHandler;
import org.jboss.weld.bootstrap.api.Singleton;
import org.jboss.weld.bootstrap.api.SingletonProvider;
import org.osgi.framework.Bundle;
import org.osgi.framework.FrameworkUtil;

public class CurrentBundleSingletonProvider extends SingletonProvider {

    @Override
    public <T> Singleton<T> create(Class<? extends T> type) {
        return new CurrentBundleSingleton<T>();
    }

    private static class CurrentBundleSingleton<T> implements Singleton<T> {

        private final Map<Long, T> store = new Hashtable<Long, T>();

        @Override
        public T get() {
            T instance = store.get(getBundleId());
            if (instance == null) {
                throw new IllegalStateException("Singleton not set for bundle " + getBundleId());
            }
            return instance;
        }

        @Override
        public void set(T object) {
            store.put(getBundleId(), object);
        }

        @Override
        public void clear() {
            store.remove(getBundleId());
        }

        public boolean isSet() {
            return store.containsKey(getBundleId());
        }

        private Long getBundleId() {
            Class<?> currentClass = ProxyMethodHandler.currentCaller.get();
            Bundle bundle = FrameworkUtil.getBundle(currentClass);
            if (bundle != null) {
                return bundle.getBundleId();
            } else {
                throw new IllegalStateException("Can't find bundle for class " + currentClass.getName());
            }
        }
    }
}