src/org/apache/felix/framework/BundleContextImpl.java

/*
 *   Copyright 2005 The Apache Software Foundation
 *
 *   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.apache.felix.framework;

import java.io.File;
import java.io.InputStream;
import java.util.Dictionary;

import org.apache.felix.framework.ext.FelixBundleContext;
import org.osgi.framework.*;

class BundleContextImpl implements FelixBundleContext
{
    private Felix m_felix = null;
    private BundleImpl m_bundle = null;

    protected BundleContextImpl(Felix felix, BundleImpl bundle)
    {
        m_felix = felix;
        m_bundle = bundle;
    }

    public void addImportPackage() throws BundleException
    {
        throw new BundleException("Not implemented yet.");
    }

    public void removeImportPackage() throws BundleException
    {
        throw new BundleException("Not implemented yet.");
    }

    public void addExportPackage() throws BundleException
    {
        throw new BundleException("Not implemented yet.");
    }

    public void removeExportPackage() throws BundleException
    {
        throw new BundleException("Not implemented yet.");
    }

    public String getProperty(String name)
    {
        return m_felix.getProperty(name);
    }

    public Bundle getBundle()
    {
        return m_bundle;
    }

    public Filter createFilter(String expr)
        throws InvalidSyntaxException
    {
        return new FilterImpl(m_felix.getLogger(), expr);
    }

    public Bundle installBundle(String location)
        throws BundleException
    {
        return installBundle(location, null);
    }

    public Bundle installBundle(String location, InputStream is)
        throws BundleException
    {
        return m_felix.installBundle(location, is);
    }

    public Bundle getBundle(long id)
    {
        return m_felix.getBundle(id);
    }

    public Bundle[] getBundles()
    {
        return m_felix.getBundles();
    }

    public void addBundleListener(BundleListener l)
    {
        m_felix.addBundleListener(m_bundle, l);
    }

    public void removeBundleListener(BundleListener l)
    {
        m_felix.removeBundleListener(l);
    }

    public void addServiceListener(ServiceListener l)
    {
        try
        {
            addServiceListener(l, null);
        }
        catch (InvalidSyntaxException ex)
        {
            // This will not happen since the filter is null.
        }
    }

    public void addServiceListener(ServiceListener l, String s)
        throws InvalidSyntaxException
    {
        m_felix.addServiceListener(m_bundle, l, s);
    }

    public void removeServiceListener(ServiceListener l)
    {
        m_felix.removeServiceListener(l);
    }

    public void addFrameworkListener(FrameworkListener l)
    {
        m_felix.addFrameworkListener(m_bundle, l);
    }

    public void removeFrameworkListener(FrameworkListener l)
    {
        m_felix.removeFrameworkListener(l);
    }

    public ServiceRegistration registerService(
        String clazz, Object svcObj, Dictionary dict)
    {
        return registerService(new String[] { clazz }, svcObj, dict);
    }

    public ServiceRegistration registerService(
        String[] clazzes, Object svcObj, Dictionary dict)
    {
        return m_felix.registerService(m_bundle, clazzes, svcObj, dict);
    }

    public ServiceReference getServiceReference(String clazz)
    {
        try
        {
            ServiceReference[] refs = getServiceReferences(clazz, null);
            return getBestServiceReference(refs);
        }
        catch (InvalidSyntaxException ex)
        {
            m_felix.getLogger().log(LogWrapper.LOG_ERROR, "BundleContextImpl: " + ex);
        }
        return null;
    }

    private ServiceReference getBestServiceReference(ServiceReference[] refs)
    {
        if (refs == null)
        {
            return null;
        }

        if (refs.length == 1)
        {
            return refs[0];
        }

        // Loop through all service references and return
        // the "best" one according to its rank and ID.
        ServiceReference bestRef = null;
        Integer bestRank = null;
        Long bestId = null;
        for (int i = 0; i < refs.length; i++)
        {
            ServiceReference ref = refs[i];

            // The first time through the loop just
            // assume that the first reference is best.
            if (bestRef == null)
            {
                bestRef = ref;
                bestRank = (Integer) bestRef.getProperty("service.ranking");
                // The spec says no ranking defaults to zero.
                if (bestRank == null)
                {
                    bestRank = new Integer(0);
                }
                bestId = (Long) bestRef.getProperty("service.id");
            }

            // Compare current and best references to see if
            // the current reference is a better choice.
            Integer rank = (Integer) ref.getProperty("service.ranking");

            // The spec says no ranking defaults to zero.
            if (rank == null)
            {
                rank = new Integer(0);
            }

            // If the current reference ranking is greater than the
            // best ranking, then keep the current reference.
            if (bestRank.compareTo(rank) < 0)
            {
                bestRef = ref;
                bestRank = rank;
                bestId = (Long) bestRef.getProperty("service.id");
            }
            // If rankings are equal, then compare IDs and
            // keep the smallest.
            else if (bestRank.compareTo(rank) == 0)
            {
                Long id = (Long) ref.getProperty("service.id");
                // If either reference has a null ID, then keep
                // the one with a non-null ID.
                if ((bestId == null) || (id == null))
                {
                    bestRef = (bestId == null) ? ref : bestRef;
                    // bestRank = bestRank; // No need to update since they are equal.
                    bestId = (Long) bestRef.getProperty("service.id");
                }
                // Otherwise compare IDs.
                else
                {
                    // If the current reference ID is less than the
                    // best ID, then keep the current reference.
                    if (bestId.compareTo(id) > 0)
                    {
                        bestRef = ref;
                        // bestRank = bestRank; // No need to update since they are equal.
                        bestId = (Long) bestRef.getProperty("service.id");
                    }
                }
            }
        }

        return bestRef;
    }

    public ServiceReference[] getAllServiceReferences(String clazz, String filter) throws InvalidSyntaxException
    {
        // TODO: Implement BundleContext.getAllServiceReferences()
        return null;
    }

    public ServiceReference[] getServiceReferences(String clazz, String filter)
        throws InvalidSyntaxException
    {
        return m_felix.getServiceReferences(m_bundle, clazz, filter);
    }

    public Object getService(ServiceReference ref)
    {
        if (ref == null)
        {
            throw new NullPointerException("Specified service reference cannot be null.");
        }
        return m_felix.getService(m_bundle, ref);
    }

    public boolean ungetService(ServiceReference ref)
    {
        if (ref == null)
        {
            throw new NullPointerException("Specified service reference cannot be null.");
        }

        // Unget the specified service.
        return m_felix.ungetService(m_bundle, ref);
    }

    public File getDataFile(String s)
    {
        return m_felix.getDataFile(m_bundle, s);
    }
}