EchoDeviceServiceRS.java

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
 *
 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
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 * See @authors listed below
 *
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package org.dcm4che3.sample.osgi.rs;

import javax.annotation.Resource;
import javax.ws.rs.GET;
import javax.ws.rs.Path;

import org.dcm4che3.net.DeviceService;
import org.dcm4che3.sample.osgi.device.EchoDeviceService;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.BundleReference;
import org.osgi.framework.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * RESTful Service implementing a Dicom device.
 * 
 * @author Umberto Cappellini <umberto.cappellini@agfa.com>
 * 
 */
@Path("")
public class EchoDeviceServiceRS {

    private static final Logger LOG = LoggerFactory.getLogger(DeviceService.class);
        
    @Resource
    private BundleContext context;

    @GET
    @Path("running")
    public String isRunning() {
        return String.valueOf(service().isRunning());
    }

    @GET
    @Path("start")
    public void start() throws Exception {
        service().start();
    }

    @GET
    @Path("stop")
    public void stop() {
        service().stop();
    }

    @GET
    @Path("reload")
    public void reload() throws Exception {
        service().reload();
    }

    private EchoDeviceService service() {
        return lookup(EchoDeviceService.class);
    }

    private <T> T lookup(Class<T> clazz) {
        if (context == null) {
            LOG.warn("BundleContext not injected");
            context = getBundleContextFromClass(clazz);
        }
        ServiceReference<T> sref = context.getServiceReference(clazz);
        return context.getService(sref);
    }

    private <T> BundleContext getBundleContextFromClass(Class<T> clazz) {
        BundleReference bref = (BundleReference) clazz.getClassLoader();
        Bundle bundle = bref.getBundle();
        if (bundle.getState() != Bundle.ACTIVE) {
            try {
                bundle.start();
            } catch (BundleException ex) 
            {
                LOG.error("Cannot start bundle", ex);
            }
        }
        return bundle.getBundleContext();
    }

}