src/main/java/org/apache/felix/webconsole/plugins/upnp/internal/ControlServlet.java - felix-dev - Git at Google

 /*
  * 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.felix.webconsole.plugins.upnp.internal;

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.reflect.Constructor;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Dictionary;
 import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.Iterator;

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

 import org.json.JSONException;
 import org.json.JSONObject;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.ServiceReference;
 import org.osgi.service.log.LogService;
 import org.osgi.service.upnp.UPnPAction;
 import org.osgi.service.upnp.UPnPDevice;
 import org.osgi.service.upnp.UPnPIcon;
 import org.osgi.service.upnp.UPnPLocalStateVariable;
 import org.osgi.service.upnp.UPnPService;
 import org.osgi.service.upnp.UPnPStateVariable;
 import org.osgi.util.tracker.ServiceTracker;
 import org.osgi.util.tracker.ServiceTrackerCustomizer;

 /**
  * This class handles requests from the Web Interface. It is separated from
  * the WebConsolePlugin just to improve readability. This servlet actually
  * is not registered in HTTP service.
  */
 public class ControlServlet extends HttpServlet implements ServiceTrackerCustomizer
 {

     private static final SimpleDateFormat DATA_FORMAT = new SimpleDateFormat(
         "EEE, d MMM yyyy HH:mm:ss Z"); //$NON-NLS-1$

     final HashMap icons = new HashMap(10);
     final HashMap sessions = new HashMap(10);

     private ServiceTracker tracker;
     private final BundleContext bc;

     private static final long LAST_MODIFIED = System.currentTimeMillis();

     /**
      * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
      *      javax.servlet.http.HttpServletResponse)
      */
     protected void doGet(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException
     {

         String udn = request.getParameter("icon"); //$NON-NLS-1$

         if (udn != null)
         {
             UPnPIcon icon = (UPnPIcon) icons.get(udn);
             if (icon == null)
             {
                 response.sendError(HttpServletResponse.SC_NOT_FOUND);
             }
             else
             {
                 if (request.getDateHeader("If-Modified-Since") > 0) //$NON-NLS-1$
                 {
                     // if it is already in cache - don't bother to go further
                     response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
                 }
                 else
                 {
                     // enable caching
                     response.setDateHeader("Last-Modified", LAST_MODIFIED); //$NON-NLS-1$

                     InputStream in = icon.getInputStream();
                     if (null == in)
                     { // this is buggy implementations
                         response.setStatus(HttpServletResponse.SC_NOT_FOUND);
                         return;
                     }

                     String mime = icon.getMimeType();
                     if (mime != null)
                         response.setContentType(mime);
                     OutputStream out = response.getOutputStream();

                     int size = icon.getSize();
                     if (size > 0)
                         response.setContentLength(size);

                     // can't use buffer, because it's might block if reading byte[]
                     int read;
                     while (-1 != (read = in.read()))
                         out.write(read);
                 }
             }
         }
     }

     /**
      * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
      *      javax.servlet.http.HttpServletResponse)
      */
     protected void doPost(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException
     {
         try
         {
             JSONObject json = new JSONObject();

             String method = request.getParameter("action"); //$NON-NLS-1$

             if ("listDevices".equals(method)) //$NON-NLS-1$
             {
                 getSession(request).unsubscribe();

                 ServiceReference[] refs = tracker.getServiceReferences();
                 // add root devices only
                 for (int i = 0; refs != null && i < refs.length; i++)
                 {
                     if (refs[i] != null
                         && refs[i].getProperty(UPnPDevice.PARENT_UDN) == null)
                     {
                         JSONObject deviceJSON = deviceTreeToJSON(refs[i]);
                         if (null != deviceJSON)
                         {
                             json.append("devices", deviceJSON); //$NON-NLS-1$
                         }
                     }
                 }
             }
             else if ("serviceDetails".equals(method)) //$NON-NLS-1$
             {
                 UPnPService service = requireService(request);
                 SessionObject session = getSession(request)//
                 .subscribe(require("udn", request), service.getId()); //$NON-NLS-1$

                 json = serviceToJSON(service, session);
             }
             else if ("invokeAction".equals(method)) //$NON-NLS-1$
             {
                 UPnPService service = requireService(request);
                 UPnPAction action = service.getAction(require("actionID", request)); //$NON-NLS-1$

                 json = invoke(action, //
                     request.getParameterValues("names"), //$NON-NLS-1$
                     request.getParameterValues("vals")); //$NON-NLS-1$
             }
             else
             {
                 throw new ServletException("Invalid action: " + method);
             }

             response.setContentType("application/json"); //$NON-NLS-1$
             response.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
             response.getWriter().print(json.toString(2));
         }
         catch (ServletException e)
         {
             response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
             response.setContentType("text/plain"); //$NON-NLS-1$
             e.printStackTrace(response.getWriter());
             response.flushBuffer();
         }
         catch (Exception e)
         {
             response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
             response.setContentType("text/plain"); //$NON-NLS-1$
             e.printStackTrace(response.getWriter());
             response.flushBuffer();
         }
     }

     private final SessionObject getSession(HttpServletRequest request)
     {
         String sessionID = request.getSession().getId();
         SessionObject ret = (SessionObject) sessions.get(sessionID);
         if (ret == null)
         {
             ret = new SessionObject(bc, sessionID, sessions);
             request.getSession().setAttribute("___upnp.session.object", ret); //$NON-NLS-1$
         }
         return ret;
     }

     private static final String require(String name, HttpServletRequest request)
         throws ServletException
     {
         String value = request.getParameter(name);
         if (value == null)
             throw new ServletException("missing parameter: " + name);
         return value;
     }

     private final UPnPService requireService(HttpServletRequest request)
         throws ServletException
     {
         String deviceUdn = require("udn", request); //$NON-NLS-1$
         String serviceUrn = require("urn", request); //$NON-NLS-1$

         UPnPDevice device = getDevice(deviceUdn);
         return getService(device, serviceUrn);
     }

     private final JSONObject deviceTreeToJSON(ServiceReference ref) throws JSONException
     {
         UPnPDevice device = (UPnPDevice) tracker.getService(ref);
         Object[] refs = tracker.getServiceReferences();

         Object parentUdn = ref.getProperty(UPnPDevice.UDN);
         if (parentUdn == null)
         {
             plugin.log(LogService.LOG_ERROR,
                 "Invalid device, no UDN property specified for " + device);
             return null;
         }

         JSONObject json = deviceToJSON(ref, device);

         // add child devices
         for (int i = 0; refs != null && i < refs.length; i++)
         {
             ref = (ServiceReference) refs[i];

             Object parent = ref.getProperty(UPnPDevice.PARENT_UDN);
             Object currentUDN = ref.getProperty(UPnPDevice.UDN);
             if (parent == null)
             { // no parent
                 continue;
             }
             else if (currentUDN != null && currentUDN.equals(parent))
             { // self ?
                 continue;
             }
             else if (parentUdn.equals(parent))
             {
                 device = (UPnPDevice) tracker.getService(ref);
                 JSONObject deviceJSON = deviceTreeToJSON(ref);
                 if (null != deviceJSON)
                 {
                     json.append("children", deviceJSON); //$NON-NLS-1$
                 }
             }
         }
         return json;
     }

     private static final JSONObject deviceToJSON(ServiceReference ref, UPnPDevice device)
         throws JSONException
     {
         JSONObject json = new JSONObject();
         json.put("icon", device.getIcons(null) != null); //$NON-NLS-1$

         // add properties
         String[] props = ref.getPropertyKeys();
         JSONObject _props = new JSONObject();
         for (int i = 0; props != null && i < props.length; i++)
         {
             _props.put(props[i], ref.getProperty(props[i]));
         }
         json.put("props", _props); //$NON-NLS-1$

         UPnPService[] services = device.getServices();
         for (int i = 0; services != null && i < services.length; i++)
         {
             json.append("services", services[i].getType()); //$NON-NLS-1$
         }

         return json;
     }

     private static final JSONObject serviceToJSON(UPnPService service,
         SessionObject session) throws JSONException
     {
         JSONObject json = new JSONObject();

         // add service properties
         json.put("type", service.getType()); //$NON-NLS-1$
         json.put("id", service.getId()); //$NON-NLS-1$

         // add state variables
         UPnPStateVariable[] vars = service.getStateVariables();
         for (int i = 0; vars != null && i < vars.length; i++)
         {
             Object value = null;
             if (vars[i] instanceof UPnPLocalStateVariable)
             {
                 value = ((UPnPLocalStateVariable) vars[i]).getCurrentValue();
             }

             if (value == null)
                 value = session.getValue(vars[i].getName());
             if (value == null)
                 value = "---"; //$NON-NLS-1$

             json.append("variables", new JSONObject() // //$NON-NLS-1$
             .put("name", vars[i].getName()) // //$NON-NLS-1$
             .put("value", value) // //$NON-NLS-1$
             .put("defalt", vars[i].getDefaultValue()) // //$NON-NLS-1$
             .put("min", vars[i].getMinimum()) // //$NON-NLS-1$
             .put("max", vars[i].getMaximum()) // //$NON-NLS-1$
             .put("step", vars[i].getStep()) // //$NON-NLS-1$
             .put("allowed", vars[i].getAllowedValues()) // //$NON-NLS-1$
             .put("sendsEvents", vars[i].sendsEvents()) // //$NON-NLS-1$
             );
         }

         // add actions
         UPnPAction[] actions = service.getActions();
         for (int i = 0; actions != null && i < actions.length; i++)
         {
             json.append("actions", actionToJSON(actions[i])); //$NON-NLS-1$
         }

         return json;
     }

     private static final JSONObject actionToJSON(UPnPAction action) throws JSONException
     {
         JSONObject json = new JSONObject();
         json.put("name", action.getName()); //$NON-NLS-1$
         String[] names = action.getInputArgumentNames();
         for (int i = 0; names != null && i < names.length; i++)
         {
             UPnPStateVariable variable = action.getStateVariable(names[i]);
             json.append("inVars", new JSONObject()// //$NON-NLS-1$
             .put("name", names[i])// //$NON-NLS-1$
             .put("type", variable.getUPnPDataType())); //$NON-NLS-1$
         }

         return json;

     }

     private static final JSONObject invoke(UPnPAction action, String[] names,
         String[] vals) throws Exception
     {
         JSONObject json = new JSONObject();

         // check input arguments
         Hashtable inputArgs = null;
         if (names != null && vals != null && names.length > 0
             && names.length == vals.length)
         {
             inputArgs = new Hashtable(names.length);
             for (int i = 0; i < names.length; i++)
             {
                 final UPnPStateVariable var = action.getStateVariable(names[i]);
                 final String upnpType = var.getUPnPDataType();
                 final Object argObj;
                 if (UPnPStateVariable.TYPE_STRING.equals(upnpType))
                 {
                     argObj = vals[i];
                 }
                 else if (UPnPStateVariable.TYPE_CHAR.equals(upnpType))
                 {
                     argObj = new Character(vals[i].charAt(0));
                 }
                 else if (UPnPStateVariable.TYPE_BIN_BASE64.equals(upnpType))
                 {
                     argObj = Base64.decodeBase64(vals[i]);
                 }
                 else if (UPnPStateVariable.TYPE_BIN_HEX.equals(upnpType))
                 {
                     argObj = Hex.decode(vals[i]);
                 }
                 else
                 {
                     Class javaType = var.getJavaDataType();
                     Constructor constructor = javaType.getConstructor(new Class[] { String.class });
                     argObj = constructor.newInstance(new Object[] { vals[i] });
                 }

                 inputArgs.put(names[i], argObj);
             }
         }

         // invoke
         Dictionary out = action.invoke(inputArgs);

         // prepare output arguments
         if (out != null && out.size() > 0)
         {
             for (Enumeration e = out.keys(); e.hasMoreElements();)
             {
                 String key = (String) e.nextElement();
                 UPnPStateVariable var = action.getStateVariable(key);

                 Object value = out.get(key);
                 if (value instanceof Date)
                 {
                     synchronized (DATA_FORMAT)
                     {
                         value = DATA_FORMAT.format((Date) value);
                     }
                 }
                 else if (value instanceof byte[])
                 {
                     value = hex((byte[]) value);
                 }

                 json.append("output", new JSONObject() // //$NON-NLS-1$
                 .put("name", key)// //$NON-NLS-1$
                 .put("type", var.getUPnPDataType()) // //$NON-NLS-1$
                 .put("value", value)); //$NON-NLS-1$
             }
         }
         return json;
     }

     private static final String hex(byte[] data)
     {
         if (data == null)
             return "null"; //$NON-NLS-1$
         StringBuffer sb = new StringBuffer(data.length * 3);
         synchronized (sb)
         {
             for (int i = 0; i < data.length; i++)
             {
                 sb.append(Integer.toHexString(data[i] & 0xff)).append('-');
             }
             sb.deleteCharAt(sb.length() - 1);
         }
         return sb.toString();
     }

     private final UPnPDevice getDevice(String udn)
     {
         ServiceReference[] refs = tracker.getServiceReferences();
         String _udn;
         for (int i = 0; refs != null && i < refs.length; i++)
         {
             _udn = (String) refs[i].getProperty(UPnPDevice.UDN);
             if (_udn != null && _udn.equals(udn))
             {
                 return (UPnPDevice) tracker.getService(refs[i]);
             }
         }

         throw new IllegalArgumentException("Device '" + udn + "' not found!");
     }

     private final UPnPService getService(UPnPDevice device, String urn)
     {
         UPnPService[] services = device.getServices();
         for (int i = 0; services != null && i < services.length; i++)
         {
             if (services[i].getType().equals(urn))
             {
                 return services[i];
             }
         }

         throw new IllegalArgumentException("Service '" + urn + "' not found!");
     }

     private final WebConsolePlugin plugin;

     /**
      * Creates new XML-RPC handler.
      *
      * @param bc the bundle context
      * @param iconServlet the icon servlet.
      */
     ControlServlet(BundleContext bc, ServiceTracker tracker, WebConsolePlugin plugin)
     {
         this.bc = bc;
         this.tracker = tracker;
         this.plugin = plugin;
     }

     /**
      * Cancels the scheduled timers
      */
     void close()
     {
         icons.clear();
         for (Iterator i = sessions.values().iterator(); i.hasNext();)
         {
             ((SessionObject) i.next()).unsubscribe();
         }
         sessions.clear();
     }

     /* ---------- BEGIN SERVICE TRACKER */
     /**
      * @see org.osgi.util.tracker.ServiceTrackerCustomizer#modifiedService(org.osgi.framework.ServiceReference,
      *      java.lang.Object)
      */
     public final void modifiedService(ServiceReference ref, Object serv)
     {/* unused */
     }

     /**
      * @see org.osgi.util.tracker.ServiceTrackerCustomizer#removedService(org.osgi.framework.ServiceReference,
      *      java.lang.Object)
      */
     public final void removedService(ServiceReference ref, Object serv)
     {
         icons.remove(ref.getProperty(UPnPDevice.UDN));
     }

     /**
      * @see org.osgi.util.tracker.ServiceTrackerCustomizer#addingService(org.osgi.framework.ServiceReference)
      */
     public final Object addingService(ServiceReference ref)
     {
         UPnPDevice device = (UPnPDevice) bc.getService(ref);

         UPnPIcon[] _icons = device.getIcons(null);
         if (_icons != null && _icons.length > 0)
         {
             icons.put(ref.getProperty(UPnPDevice.UDN), _icons[0]);
         }

         return device;
     }

 }
	/*
	* 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.felix.webconsole.plugins.upnp.internal;

	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.lang.reflect.Constructor;
	import java.text.SimpleDateFormat;
	import java.util.Date;
	import java.util.Dictionary;
	import java.util.Enumeration;
	import java.util.HashMap;
	import java.util.Hashtable;
	import java.util.Iterator;

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

	import org.json.JSONException;
	import org.json.JSONObject;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.ServiceReference;
	import org.osgi.service.log.LogService;
	import org.osgi.service.upnp.UPnPAction;
	import org.osgi.service.upnp.UPnPDevice;
	import org.osgi.service.upnp.UPnPIcon;
	import org.osgi.service.upnp.UPnPLocalStateVariable;
	import org.osgi.service.upnp.UPnPService;
	import org.osgi.service.upnp.UPnPStateVariable;
	import org.osgi.util.tracker.ServiceTracker;
	import org.osgi.util.tracker.ServiceTrackerCustomizer;

	/**
	* This class handles requests from the Web Interface. It is separated from
	* the WebConsolePlugin just to improve readability. This servlet actually
	* is not registered in HTTP service.
	*/
	public class ControlServlet extends HttpServlet implements ServiceTrackerCustomizer
	{

	private static final SimpleDateFormat DATA_FORMAT = new SimpleDateFormat(
	"EEE, d MMM yyyy HH:mm:ss Z"); //$NON-NLS-1$

	final HashMap icons = new HashMap(10);
	final HashMap sessions = new HashMap(10);

	private ServiceTracker tracker;
	private final BundleContext bc;

	private static final long LAST_MODIFIED = System.currentTimeMillis();

	/**
	* @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
	* javax.servlet.http.HttpServletResponse)
	*/
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException
	{

	String udn = request.getParameter("icon"); //$NON-NLS-1$

	if (udn != null)
	{
	UPnPIcon icon = (UPnPIcon) icons.get(udn);
	if (icon == null)
	{
	response.sendError(HttpServletResponse.SC_NOT_FOUND);
	}
	else
	{
	if (request.getDateHeader("If-Modified-Since") > 0) //$NON-NLS-1$
	{
	// if it is already in cache - don't bother to go further
	response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
	}
	else
	{
	// enable caching
	response.setDateHeader("Last-Modified", LAST_MODIFIED); //$NON-NLS-1$

	InputStream in = icon.getInputStream();
	if (null == in)
	{ // this is buggy implementations
	response.setStatus(HttpServletResponse.SC_NOT_FOUND);
	return;
	}

	String mime = icon.getMimeType();
	if (mime != null)
	response.setContentType(mime);
	OutputStream out = response.getOutputStream();

	int size = icon.getSize();
	if (size > 0)
	response.setContentLength(size);

	// can't use buffer, because it's might block if reading byte[]
	int read;
	while (-1 != (read = in.read()))
	out.write(read);
	}
	}
	}
	}

	/**
	* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
	* javax.servlet.http.HttpServletResponse)
	*/
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException
	{
	try
	{
	JSONObject json = new JSONObject();

	String method = request.getParameter("action"); //$NON-NLS-1$

	if ("listDevices".equals(method)) //$NON-NLS-1$
	{
	getSession(request).unsubscribe();

	ServiceReference[] refs = tracker.getServiceReferences();
	// add root devices only
	for (int i = 0; refs != null && i < refs.length; i++)
	{
	if (refs[i] != null
	&& refs[i].getProperty(UPnPDevice.PARENT_UDN) == null)
	{
	JSONObject deviceJSON = deviceTreeToJSON(refs[i]);
	if (null != deviceJSON)
	{
	json.append("devices", deviceJSON); //$NON-NLS-1$
	}
	}
	}
	}
	else if ("serviceDetails".equals(method)) //$NON-NLS-1$
	{
	UPnPService service = requireService(request);
	SessionObject session = getSession(request)//
	.subscribe(require("udn", request), service.getId()); //$NON-NLS-1$

	json = serviceToJSON(service, session);
	}
	else if ("invokeAction".equals(method)) //$NON-NLS-1$
	{
	UPnPService service = requireService(request);
	UPnPAction action = service.getAction(require("actionID", request)); //$NON-NLS-1$

	json = invoke(action, //
	request.getParameterValues("names"), //$NON-NLS-1$
	request.getParameterValues("vals")); //$NON-NLS-1$
	}
	else
	{
	throw new ServletException("Invalid action: " + method);
	}

	response.setContentType("application/json"); //$NON-NLS-1$
	response.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
	response.getWriter().print(json.toString(2));
	}
	catch (ServletException e)
	{
	response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
	response.setContentType("text/plain"); //$NON-NLS-1$
	e.printStackTrace(response.getWriter());
	response.flushBuffer();
	}
	catch (Exception e)
	{
	response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
	response.setContentType("text/plain"); //$NON-NLS-1$
	e.printStackTrace(response.getWriter());
	response.flushBuffer();
	}
	}

	private final SessionObject getSession(HttpServletRequest request)
	{
	String sessionID = request.getSession().getId();
	SessionObject ret = (SessionObject) sessions.get(sessionID);
	if (ret == null)
	{
	ret = new SessionObject(bc, sessionID, sessions);
	request.getSession().setAttribute("___upnp.session.object", ret); //$NON-NLS-1$
	}
	return ret;
	}

	private static final String require(String name, HttpServletRequest request)
	throws ServletException
	{
	String value = request.getParameter(name);
	if (value == null)
	throw new ServletException("missing parameter: " + name);
	return value;
	}

	private final UPnPService requireService(HttpServletRequest request)
	throws ServletException
	{
	String deviceUdn = require("udn", request); //$NON-NLS-1$
	String serviceUrn = require("urn", request); //$NON-NLS-1$

	UPnPDevice device = getDevice(deviceUdn);
	return getService(device, serviceUrn);
	}

	private final JSONObject deviceTreeToJSON(ServiceReference ref) throws JSONException
	{
	UPnPDevice device = (UPnPDevice) tracker.getService(ref);
	Object[] refs = tracker.getServiceReferences();

	Object parentUdn = ref.getProperty(UPnPDevice.UDN);
	if (parentUdn == null)
	{
	plugin.log(LogService.LOG_ERROR,
	"Invalid device, no UDN property specified for " + device);
	return null;
	}

	JSONObject json = deviceToJSON(ref, device);

	// add child devices
	for (int i = 0; refs != null && i < refs.length; i++)
	{
	ref = (ServiceReference) refs[i];

	Object parent = ref.getProperty(UPnPDevice.PARENT_UDN);
	Object currentUDN = ref.getProperty(UPnPDevice.UDN);
	if (parent == null)
	{ // no parent
	continue;
	}
	else if (currentUDN != null && currentUDN.equals(parent))
	{ // self ?
	continue;
	}
	else if (parentUdn.equals(parent))
	{
	device = (UPnPDevice) tracker.getService(ref);
	JSONObject deviceJSON = deviceTreeToJSON(ref);
	if (null != deviceJSON)
	{
	json.append("children", deviceJSON); //$NON-NLS-1$
	}
	}
	}
	return json;
	}

	private static final JSONObject deviceToJSON(ServiceReference ref, UPnPDevice device)
	throws JSONException
	{
	JSONObject json = new JSONObject();
	json.put("icon", device.getIcons(null) != null); //$NON-NLS-1$

	// add properties
	String[] props = ref.getPropertyKeys();
	JSONObject _props = new JSONObject();
	for (int i = 0; props != null && i < props.length; i++)
	{
	_props.put(props[i], ref.getProperty(props[i]));
	}
	json.put("props", _props); //$NON-NLS-1$

	UPnPService[] services = device.getServices();
	for (int i = 0; services != null && i < services.length; i++)
	{
	json.append("services", services[i].getType()); //$NON-NLS-1$
	}

	return json;
	}

	private static final JSONObject serviceToJSON(UPnPService service,
	SessionObject session) throws JSONException
	{
	JSONObject json = new JSONObject();

	// add service properties
	json.put("type", service.getType()); //$NON-NLS-1$
	json.put("id", service.getId()); //$NON-NLS-1$

	// add state variables
	UPnPStateVariable[] vars = service.getStateVariables();
	for (int i = 0; vars != null && i < vars.length; i++)
	{
	Object value = null;
	if (vars[i] instanceof UPnPLocalStateVariable)
	{
	value = ((UPnPLocalStateVariable) vars[i]).getCurrentValue();
	}

	if (value == null)
	value = session.getValue(vars[i].getName());
	if (value == null)
	value = "---"; //$NON-NLS-1$

	json.append("variables", new JSONObject() // //$NON-NLS-1$
	.put("name", vars[i].getName()) // //$NON-NLS-1$
	.put("value", value) // //$NON-NLS-1$
	.put("defalt", vars[i].getDefaultValue()) // //$NON-NLS-1$
	.put("min", vars[i].getMinimum()) // //$NON-NLS-1$
	.put("max", vars[i].getMaximum()) // //$NON-NLS-1$
	.put("step", vars[i].getStep()) // //$NON-NLS-1$
	.put("allowed", vars[i].getAllowedValues()) // //$NON-NLS-1$
	.put("sendsEvents", vars[i].sendsEvents()) // //$NON-NLS-1$
	);
	}

	// add actions
	UPnPAction[] actions = service.getActions();
	for (int i = 0; actions != null && i < actions.length; i++)
	{
	json.append("actions", actionToJSON(actions[i])); //$NON-NLS-1$
	}

	return json;
	}

	private static final JSONObject actionToJSON(UPnPAction action) throws JSONException
	{
	JSONObject json = new JSONObject();
	json.put("name", action.getName()); //$NON-NLS-1$
	String[] names = action.getInputArgumentNames();
	for (int i = 0; names != null && i < names.length; i++)
	{
	UPnPStateVariable variable = action.getStateVariable(names[i]);
	json.append("inVars", new JSONObject()// //$NON-NLS-1$
	.put("name", names[i])// //$NON-NLS-1$
	.put("type", variable.getUPnPDataType())); //$NON-NLS-1$
	}

	return json;

	}

	private static final JSONObject invoke(UPnPAction action, String[] names,
	String[] vals) throws Exception
	{
	JSONObject json = new JSONObject();

	// check input arguments
	Hashtable inputArgs = null;
	if (names != null && vals != null && names.length > 0
	&& names.length == vals.length)
	{
	inputArgs = new Hashtable(names.length);
	for (int i = 0; i < names.length; i++)
	{
	final UPnPStateVariable var = action.getStateVariable(names[i]);
	final String upnpType = var.getUPnPDataType();
	final Object argObj;
	if (UPnPStateVariable.TYPE_STRING.equals(upnpType))
	{
	argObj = vals[i];
	}
	else if (UPnPStateVariable.TYPE_CHAR.equals(upnpType))
	{
	argObj = new Character(vals[i].charAt(0));
	}
	else if (UPnPStateVariable.TYPE_BIN_BASE64.equals(upnpType))
	{
	argObj = Base64.decodeBase64(vals[i]);
	}
	else if (UPnPStateVariable.TYPE_BIN_HEX.equals(upnpType))
	{
	argObj = Hex.decode(vals[i]);
	}
	else
	{
	Class javaType = var.getJavaDataType();
	Constructor constructor = javaType.getConstructor(new Class[] { String.class });
	argObj = constructor.newInstance(new Object[] { vals[i] });
	}

	inputArgs.put(names[i], argObj);
	}
	}

	// invoke
	Dictionary out = action.invoke(inputArgs);

	// prepare output arguments
	if (out != null && out.size() > 0)
	{
	for (Enumeration e = out.keys(); e.hasMoreElements();)
	{
	String key = (String) e.nextElement();
	UPnPStateVariable var = action.getStateVariable(key);

	Object value = out.get(key);
	if (value instanceof Date)
	{
	synchronized (DATA_FORMAT)
	{
	value = DATA_FORMAT.format((Date) value);
	}
	}
	else if (value instanceof byte[])
	{
	value = hex((byte[]) value);
	}

	json.append("output", new JSONObject() // //$NON-NLS-1$
	.put("name", key)// //$NON-NLS-1$
	.put("type", var.getUPnPDataType()) // //$NON-NLS-1$
	.put("value", value)); //$NON-NLS-1$
	}
	}
	return json;
	}

	private static final String hex(byte[] data)
	{
	if (data == null)
	return "null"; //$NON-NLS-1$
	StringBuffer sb = new StringBuffer(data.length * 3);
	synchronized (sb)
	{
	for (int i = 0; i < data.length; i++)
	{
	sb.append(Integer.toHexString(data[i] & 0xff)).append('-');
	}
	sb.deleteCharAt(sb.length() - 1);
	}
	return sb.toString();
	}

	private final UPnPDevice getDevice(String udn)
	{
	ServiceReference[] refs = tracker.getServiceReferences();
	String _udn;
	for (int i = 0; refs != null && i < refs.length; i++)
	{
	_udn = (String) refs[i].getProperty(UPnPDevice.UDN);
	if (_udn != null && _udn.equals(udn))
	{
	return (UPnPDevice) tracker.getService(refs[i]);
	}
	}

	throw new IllegalArgumentException("Device '" + udn + "' not found!");
	}

	private final UPnPService getService(UPnPDevice device, String urn)
	{
	UPnPService[] services = device.getServices();
	for (int i = 0; services != null && i < services.length; i++)
	{
	if (services[i].getType().equals(urn))
	{
	return services[i];
	}
	}

	throw new IllegalArgumentException("Service '" + urn + "' not found!");
	}

	private final WebConsolePlugin plugin;

	/**
	* Creates new XML-RPC handler.
	*
	* @param bc the bundle context
	* @param iconServlet the icon servlet.
	*/
	ControlServlet(BundleContext bc, ServiceTracker tracker, WebConsolePlugin plugin)
	{
	this.bc = bc;
	this.tracker = tracker;
	this.plugin = plugin;
	}

	/**
	* Cancels the scheduled timers
	*/
	void close()
	{
	icons.clear();
	for (Iterator i = sessions.values().iterator(); i.hasNext();)
	{
	((SessionObject) i.next()).unsubscribe();
	}
	sessions.clear();
	}

	/* ---------- BEGIN SERVICE TRACKER */
	/**
	* @see org.osgi.util.tracker.ServiceTrackerCustomizer#modifiedService(org.osgi.framework.ServiceReference,
	* java.lang.Object)
	*/
	public final void modifiedService(ServiceReference ref, Object serv)
	{/* unused */
	}

	/**
	* @see org.osgi.util.tracker.ServiceTrackerCustomizer#removedService(org.osgi.framework.ServiceReference,
	* java.lang.Object)
	*/
	public final void removedService(ServiceReference ref, Object serv)
	{
	icons.remove(ref.getProperty(UPnPDevice.UDN));
	}

	/**
	* @see org.osgi.util.tracker.ServiceTrackerCustomizer#addingService(org.osgi.framework.ServiceReference)
	*/
	public final Object addingService(ServiceReference ref)
	{
	UPnPDevice device = (UPnPDevice) bc.getService(ref);

	UPnPIcon[] _icons = device.getIcons(null);
	if (_icons != null && _icons.length > 0)
	{
	icons.put(ref.getProperty(UPnPDevice.UDN), _icons[0]);
	}

	return device;
	}

	}