io.wcm.caravan.jaxrs.publisher.impl.JaxRsBundleTracker.java Source code

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Here is the source code for io.wcm.caravan.jaxrs.publisher.impl.JaxRsBundleTracker.java

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/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2015 wcm.io
 * %%
 * 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.
 * #L%
 */
package io.wcm.caravan.jaxrs.publisher.impl;

import io.wcm.caravan.jaxrs.publisher.ApplicationPath;

import java.util.Dictionary;
import java.util.Hashtable;

import org.apache.commons.lang3.StringUtils;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Reference;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleEvent;
import org.osgi.service.component.ComponentConstants;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.component.ComponentFactory;
import org.osgi.service.component.ComponentInstance;
import org.osgi.util.tracker.BundleTracker;
import org.osgi.util.tracker.BundleTrackerCustomizer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Bundle tracker that listens for all bundles added to the OSGi systems, and searches for JAX-RS components.
 * If any is found and an application path is defined a jersey instance dedicated to this bundle is instantiated.
 */
@Component(immediate = true)
public class JaxRsBundleTracker implements BundleTrackerCustomizer<ComponentInstance> {

    private static final Logger log = LoggerFactory.getLogger(JaxRsBundleTracker.class);

    private BundleContext bundleContext;
    private BundleTracker bundleTracker;

    @Reference(target = "(" + ComponentConstants.COMPONENT_FACTORY + "="
            + ServletContainerBridge.SERVLETCONTAINER_BRIDGE_FACTORY + ")")
    private ComponentFactory servletContainerBridgeFactory;

    @Activate
    void activate(ComponentContext componentContext) {
        bundleContext = componentContext.getBundleContext();
        this.bundleTracker = new BundleTracker<ComponentInstance>(bundleContext, Bundle.ACTIVE, this);
        this.bundleTracker.open();
    }

    @Deactivate
    void deactivate(ComponentContext componentContext) {
        this.bundleTracker.close();
    }

    @Override
    public ComponentInstance addingBundle(Bundle bundle, BundleEvent event) {
        String applicationPath = ApplicationPath.get(bundle);
        if (StringUtils.isNotBlank(applicationPath)) {

            if (log.isInfoEnabled()) {
                log.info("Mount JAX-RS application {} to {}", bundle.getSymbolicName(), applicationPath);
            }

            // register JAX-RS application as servlet on HTTP whiteboard
            Dictionary<String, Object> serviceConfig = new Hashtable<>();
            serviceConfig.put("alias", applicationPath);
            serviceConfig.put(ServletContainerBridge.PROPERTY_BUNDLE, bundle);
            return servletContainerBridgeFactory.newInstance(serviceConfig);
        }
        return null;
    }

    @Override
    public void modifiedBundle(Bundle bundle, BundleEvent event, ComponentInstance componentInstance) {
        // nothing to do
    }

    @Override
    public void removedBundle(Bundle bundle, BundleEvent event, ComponentInstance componentInstance) {
        if (componentInstance == null) {
            return;
        }
        if (log.isInfoEnabled()) {
            String applicationPath = ApplicationPath.get(bundle);
            log.info("Unmount JAX-RS application {} from {}", bundle.getSymbolicName(), applicationPath);
        }
        componentInstance.dispose();
    }

}