org.opengoss.core.internal.registry.ApplicationServiceRegistry.java Source code

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Here is the source code for org.opengoss.core.internal.registry.ApplicationServiceRegistry.java

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/*
 * Copyright 2005-2006 the original authors and www.opengoss.org community.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.opengoss.core.internal.registry;

import java.rmi.Remote;
import java.util.Dictionary;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.opengoss.core.INetworkServiceRegistry;
import org.opengoss.core.IRegistry;
import org.opengoss.core.IApplicationServiceRegistry;
import org.opengoss.core.Registry;
import org.opengoss.core.UID;
import org.opengoss.core.internal.ServiceHolder;
import org.opengoss.core.internal.descriptor.Constants;
import org.opengoss.core.internal.descriptor.ServiceDescriptor;
import org.opengoss.core.internal.descriptor.ServiceScope;
import org.opengoss.core.util.AssertException;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;

/**
 * Application level service registry that wraps OSGi service registry.
 * 
 * @author Ery Lee(ery.lee@gmail.com)
 * @version 1.0 2006-11-19
 */
public class ApplicationServiceRegistry extends Registry implements IApplicationServiceRegistry {

    static final String APPLICATION_NAME = "org.opengoss.core.application";

    static final String DEFAULT_APPLICATION = "Default";

    static final Log log = LogFactory.getLog(ApplicationServiceRegistry.class);

    private String application;

    private Map<UID, ServiceRegistration> cache = new HashMap<UID, ServiceRegistration>();

    public ApplicationServiceRegistry() {
        this(null);
    }

    public ApplicationServiceRegistry(IRegistry parent) {
        super(parent);
        this.application = System.getProperty(APPLICATION_NAME);
        if (this.application == null) {
            this.application = DEFAULT_APPLICATION;
        }
    }

    public Object getService(BundleContext context, String id) {
        return getService(context, id, null);
    }

    public <T> T getService(BundleContext context, Class<T> intf) {
        return getService(context, null, intf);
    }

    public <T> T getService(BundleContext context, String id, Class<T> intf) {
        T service = getFromOSGi(context, id, intf);
        if (service == null) {
            if (getParent() != null) {
                service = (T) ((INetworkServiceRegistry) getParent()).getService(id, intf);
            }
        }
        return service;
    }

    public void registerService(ServiceHolder holder) throws Exception {
        //register service in osgi.
        ServiceDescriptor descriptor = holder.getDescriptor();
        UID serviceUid = descriptor.getGlobalUid();
        Dictionary<String, String> props = serviceUid.toDictionary();
        props.put(Constants.SCOPE, descriptor.getScope().toString());
        ServiceRegistration reg = ((PluginServiceRegistry) holder.getRegistry()).getBundleContext()
                .registerService(descriptor.getInterfaces(), holder.getService(), props);
        cache.put(serviceUid, reg);
        //register service to network registry.
        if (descriptor.getScope() == (ServiceScope.NETWORK)) {
            ((INetworkServiceRegistry) getParent()).register(application + ":" + serviceUid.getId(),
                    (Remote) holder.getService());
        }
    }

    public void unregisterService(ServiceHolder holder) throws Exception {
        UID uid = holder.getDescriptor().getGlobalUid();
        //unregister from network registry.
        if (holder.getDescriptor().getScope() == (ServiceScope.NETWORK)) {
            ((INetworkServiceRegistry) getParent()).unregister(application + ":" + uid.getId());
        }
        //unregister from osgi.
        ServiceRegistration reg = cache.remove(uid);
        if (reg != null) {
            reg.unregister();
        }
    }

    @SuppressWarnings("unchecked")
    private <T> T getFromOSGi(BundleContext context, String id, Class<T> intf) {
        T service = null;
        String filter = null;
        if (id != null) {
            filter = new UID(id).toFilter();
        }
        String intfName = null;
        if (intf != null) {
            intfName = intf.getName();
        }
        try {
            ServiceReference[] refs = context.getServiceReferences(intfName, filter);
            if (refs == null || refs.length == 0) {
                log.warn("No service found in OSGi! id= " + id + ", filter=" + filter);
            } else if (refs.length > 1) {
                log.warn("More than one services found in OSGi! id= " + id + ", filter=" + filter);
            } else { //refs.length == 1
                service = (T) context.getService(refs[0]);
            }
            return service;
        } catch (InvalidSyntaxException e) {
            throw new AssertException("!Invalid filter syntax: " + filter, e);
        }

    }

}