org.eclipse.gyrex.admin.ui.internal.servlets.AdminServletTracker.java Source code

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Here is the source code for org.eclipse.gyrex.admin.ui.internal.servlets.AdminServletTracker.java

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/*******************************************************************************
 * Copyright (c) 2013 AGETO Service GmbH and others.
 * All rights reserved.
 *  
 * This program and the accompanying materials are made available under the 
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 * 
 * Contributors:
 *     Gunnar Wagenknecht - initial API and implementation
 *******************************************************************************/
package org.eclipse.gyrex.admin.ui.internal.servlets;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.gyrex.admin.ui.internal.jetty.AdminServletHolder;

import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.servlet.ServletMapping;

import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.util.tracker.ServiceTracker;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.exception.ExceptionUtils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Tracker for {@link IAdminServlet}.
 */
public class AdminServletTracker extends ServiceTracker<IAdminServlet, AdminServletHolder> {

    private static final Logger LOG = LoggerFactory.getLogger(AdminServletTracker.class);

    private final ServletContextHandler contextHandler;

    public AdminServletTracker(final BundleContext context, final ServletContextHandler contextHandler) {
        super(context, IAdminServlet.class, null);
        this.contextHandler = contextHandler;
    }

    @Override
    public AdminServletHolder addingService(final ServiceReference<IAdminServlet> reference) {
        final IAdminServlet servlet = context.getService(reference);
        if (servlet == null)
            return null;
        final AdminServletHolder holder = new AdminServletHolder(servlet);
        final Object alias = reference.getProperty("http.alias");
        if (alias instanceof String) {
            String pathSpec = (String) alias;
            // convert to path spec
            if (!StringUtils.endsWith(pathSpec, "/*")) {
                pathSpec = StringUtils.removeEnd(pathSpec, "/") + "/*";
            }

            try {
                // register servlet
                contextHandler.getServletHandler().addServlet(holder);

                // create, remember & register mapping
                final ServletMapping mapping = new ServletMapping();
                mapping.setPathSpec(pathSpec);
                mapping.setServletName(holder.getName());
                holder.setServletMapping(mapping);
                contextHandler.getServletHandler().addServletMapping(mapping);
            } catch (final Exception e) {
                LOG.error("Error registering contributed servlet {} ({}). {}", reference, pathSpec,
                        ExceptionUtils.getRootCauseMessage(e), e);
            }
        }
        return holder;
    }

    @Override
    public void removedService(final ServiceReference<IAdminServlet> reference, final AdminServletHolder holder) {
        try {
            // remove mapping
            final ServletMapping[] mappings = contextHandler.getServletHandler().getServletMappings();
            final List<ServletMapping> newMappings = new ArrayList<>();
            for (final ServletMapping servletMapping : mappings) {
                if (servletMapping != holder.getServletMapping()) {
                    newMappings.add(servletMapping);
                }
            }
            contextHandler.getServletHandler()
                    .setServletMappings(newMappings.toArray(new ServletMapping[newMappings.size()]));

            // remove servlet
            final ServletHolder[] holders = contextHandler.getServletHandler().getServlets();
            final List<ServletHolder> newHolders = new ArrayList<>();
            for (final ServletHolder servletHolder : holders) {
                if (holder != servletHolder) {
                    newHolders.add(servletHolder);
                }
            }
            contextHandler.getServletHandler()
                    .setServlets(newHolders.toArray(new ServletHolder[newHolders.size()]));
        } finally {
            // unget servlet
            context.ungetService(reference);
        }
    }
}