AdapterWebConsolePlugin POC

gistfile1.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You 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.sling.adapter.internal;

import static org.apache.sling.api.adapter.AdapterFactory.*;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.commons.osgi.OsgiUtil;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.Filter;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.service.component.ComponentContext;
import org.osgi.util.tracker.ServiceTracker;
import org.osgi.util.tracker.ServiceTrackerCustomizer;

@Component
@Service(Servlet.class)
@Properties({ @Property(name = Constants.SERVICE_DESCRIPTION, value = "Adapter Web Console Plugin"),
        @Property(name = Constants.SERVICE_VENDOR, value = "The Apache Software Foundation"),
        @Property(name = "felix.webconsole.label", value = "adapters"),
        @Property(name = "felix.webconsole.title", value = "Sling Adapters")

})
@SuppressWarnings("serial")
public class AdapterWebConsolePlugin extends HttpServlet implements ServiceTrackerCustomizer {

    private Map<String, List<String>> adaptableMap;
    private Map<Object, AdapterDescription> adapters;

    private ServiceTracker adapterTracker;

    private BundleContext bundleContext;

    public Object addingService(ServiceReference reference) {
        Object service = this.bundleContext.getService(reference);
        adapters.put(service, createDescription(reference));
        update();
        return service;
    }

    public void modifiedService(ServiceReference reference, Object service) {
        adapters.put(service, createDescription(reference));
        update();
    }
    
    public void removedService(ServiceReference reference, Object service) {
        adapters.remove(service);
    }

    private AdapterDescription createDescription(ServiceReference reference) {
        AdapterDescription desc = new AdapterDescription();
        desc.adaptables = OsgiUtil.toStringArray(reference.getProperty(ADAPTABLE_CLASSES));
        desc.adapters = OsgiUtil.toStringArray(reference.getProperty(ADAPTER_CLASSES));
        desc.condition = OsgiUtil.toString(reference.getProperty("adapter.condition"), null);
        desc.bundle = reference.getBundle();
        return desc;
    }

    private void update() {
        Map<String, List<String>> newMap = new TreeMap<String, List<String>>();
        for (AdapterDescription desc : adapters.values()) {
            for (String adaptable : desc.adaptables) {
                List<String> list = newMap.get(adaptable);
                if (list == null) {
                    list = new ArrayList<String>();
                    newMap.put(adaptable, list);
                }
                list.addAll(Arrays.asList(desc.adapters));
            }
        }
        adaptableMap = newMap;
    }

    protected void activate(ComponentContext ctx) throws InvalidSyntaxException {
        this.bundleContext = ctx.getBundleContext();
        this.adapters = new HashMap<Object, AdapterDescription>();
        Filter filter = this.bundleContext.createFilter("(&(adaptables=*)(adapters=*))");
        this.adapterTracker = new ServiceTracker(this.bundleContext, filter, this);
        this.adapterTracker.open();
    }

    protected void deactivate(ComponentContext ctx) {
        this.adapterTracker.close();
        this.adapters = null;
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println(adapters.toString());
        resp.getWriter().println(adaptableMap.toString());
    }

    class AdapterDescription {
        private String[] adaptables;
        private String[] adapters;
        private Bundle bundle;
        private String condition;
        
        @Override
        public String toString() {
            return "AdapterDescription [adaptables=" + Arrays.toString(adaptables) + ", adapters="
                    + Arrays.toString(adapters) + ", condition=" + condition + ", bundle=" + bundle + "]";
        }
        
    }

}