Java tutorial
/******************************************************************************* * Copyright (c) 2013-2015 Sierra Wireless and others. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * and Eclipse Distribution License v1.0 which accompany this distribution. * * The Eclipse Public License is available at * http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.html. * * Contributors: * Sierra Wireless - initial API and implementation *******************************************************************************/ package org.eclipse.leshan.standalone.servlet; import java.io.IOException; import java.util.Collection; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringUtils; import org.eclipse.jetty.http.HttpFields; import org.eclipse.leshan.core.node.LwM2mNode; import org.eclipse.leshan.core.node.LwM2mObjectInstance; import org.eclipse.leshan.core.node.LwM2mResource; import org.eclipse.leshan.core.node.Value; import org.eclipse.leshan.core.request.ContentFormat; import org.eclipse.leshan.core.request.CreateRequest; import org.eclipse.leshan.core.request.DeleteRequest; import org.eclipse.leshan.core.request.ExecuteRequest; import org.eclipse.leshan.core.request.ObserveRequest; import org.eclipse.leshan.core.request.ReadRequest; import org.eclipse.leshan.core.request.WriteRequest; import org.eclipse.leshan.core.request.exception.RequestFailedException; import org.eclipse.leshan.core.request.exception.ResourceAccessException; import org.eclipse.leshan.core.response.LwM2mResponse; import org.eclipse.leshan.core.response.ValueResponse; import org.eclipse.leshan.server.LwM2mServer; import org.eclipse.leshan.server.client.Client; import org.eclipse.leshan.standalone.servlet.json.ClientSerializer; import org.eclipse.leshan.standalone.servlet.json.LwM2mNodeDeserializer; import org.eclipse.leshan.standalone.servlet.json.LwM2mNodeSerializer; import org.eclipse.leshan.standalone.servlet.json.ResponseSerializer; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonSyntaxException; /** * Service HTTP REST API calls. */ public class ClientServlet extends HttpServlet { private static final Logger LOG = LoggerFactory.getLogger(ClientServlet.class); private static final long TIMEOUT = 5000; // ms private static final long serialVersionUID = 1L; private final LwM2mServer server; private final Gson gson; public ClientServlet(LwM2mServer server) { this.server = server; GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeHierarchyAdapter(Client.class, new ClientSerializer()); gsonBuilder.registerTypeHierarchyAdapter(LwM2mResponse.class, new ResponseSerializer()); gsonBuilder.registerTypeHierarchyAdapter(LwM2mNode.class, new LwM2mNodeSerializer()); gsonBuilder.registerTypeHierarchyAdapter(LwM2mNode.class, new LwM2mNodeDeserializer()); gsonBuilder.setDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX"); this.gson = gsonBuilder.create(); } /** * {@inheritDoc} */ @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // all registered clients if (req.getPathInfo() == null) { Collection<Client> clients = server.getClientRegistry().allClients(); String json = this.gson.toJson(clients.toArray(new Client[] {})); resp.setContentType("application/json"); resp.getOutputStream().write(json.getBytes("UTF-8")); resp.setStatus(HttpServletResponse.SC_OK); return; } String[] path = StringUtils.split(req.getPathInfo(), '/'); if (path.length < 1) { resp.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid path"); return; } String clientEndpoint = path[0]; // /endPoint : get client if (path.length == 1) { Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { resp.setContentType("application/json"); resp.getOutputStream().write(this.gson.toJson(client).getBytes("UTF-8")); resp.setStatus(HttpServletResponse.SC_OK); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } return; } // /clients/endPoint/LWRequest : do LightWeight M2M read request on a given client. try { String target = StringUtils.removeStart(req.getPathInfo(), "/" + clientEndpoint); Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { ReadRequest request = new ReadRequest(target); ValueResponse cResponse = server.send(client, request, TIMEOUT); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("No registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } } /** * {@inheritDoc} */ @Override protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String[] path = StringUtils.split(req.getPathInfo(), '/'); String clientEndpoint = path[0]; // at least /endpoint/objectId/instanceId if (path.length < 3) { resp.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid path"); return; } try { String target = StringUtils.removeStart(req.getPathInfo(), "/" + clientEndpoint); Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { LwM2mResponse cResponse = this.writeRequest(client, target, req, resp); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("No registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } } /** * {@inheritDoc} */ @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String[] path = StringUtils.split(req.getPathInfo(), '/'); String clientEndpoint = path[0]; // /clients/endPoint/LWRequest/observe : do LightWeight M2M observe request on a given client. if (path.length >= 4 && "observe".equals(path[path.length - 1])) { try { String target = StringUtils.substringBetween(req.getPathInfo(), clientEndpoint, "/observe"); Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { ObserveRequest request = new ObserveRequest(target); LwM2mResponse cResponse = server.send(client, request, TIMEOUT); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } return; } String target = StringUtils.removeStart(req.getPathInfo(), "/" + clientEndpoint); // /clients/endPoint/LWRequest : do LightWeight M2M execute request on a given client. if (path.length == 4) { try { Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { ExecuteRequest request = new ExecuteRequest(target, IOUtils.toByteArray(req.getInputStream()), null); LwM2mResponse cResponse = server.send(client, request, TIMEOUT); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } return; } // /clients/endPoint/LWRequest : do LightWeight M2M create request on a given client. if (2 <= path.length && path.length <= 3) { try { Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { LwM2mResponse cResponse = this.createRequest(client, target, req, resp); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } return; } } @Override protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String[] path = StringUtils.split(req.getPathInfo(), '/'); String clientEndpoint = path[0]; // /clients/endPoint/LWRequest/observe : cancel observation for the given resource. if (path.length >= 4 && "observe".equals(path[path.length - 1])) { try { String target = StringUtils.substringsBetween(req.getPathInfo(), clientEndpoint, "/observe")[0]; Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { server.getObservationRegistry().cancelObservation(client, target); resp.setStatus(HttpServletResponse.SC_OK); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } return; } // /clients/endPoint/LWRequest/ : delete instance try { String target = StringUtils.removeStart(req.getPathInfo(), "/" + clientEndpoint); Client client = server.getClientRegistry().get(clientEndpoint); if (client != null) { DeleteRequest request = new DeleteRequest(target); LwM2mResponse cResponse = server.send(client, request, TIMEOUT); processDeviceResponse(req, resp, cResponse); } else { resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().format("no registered client with id '%s'", clientEndpoint).flush(); } } catch (IllegalArgumentException e) { LOG.warn("Invalid request", e); resp.setStatus(HttpServletResponse.SC_BAD_REQUEST); resp.getWriter().append(e.getMessage()).flush(); } catch (ResourceAccessException | RequestFailedException e) { LOG.warn(String.format("Error accessing resource %s%s.", req.getServletPath(), req.getPathInfo()), e); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append(e.getMessage()).flush(); } } private void processDeviceResponse(HttpServletRequest req, HttpServletResponse resp, LwM2mResponse cResponse) throws IOException { String response = null; if (cResponse == null) { LOG.warn(String.format("Request %s%s timed out.", req.getServletPath(), req.getPathInfo())); resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); resp.getWriter().append("Request timeout").flush(); } else { response = this.gson.toJson(cResponse); resp.setContentType("application/json"); resp.getOutputStream().write(response.getBytes()); resp.setStatus(HttpServletResponse.SC_OK); } } // TODO refactor the code to remove this method. private LwM2mResponse writeRequest(Client client, String target, HttpServletRequest req, HttpServletResponse resp) throws IOException { Map<String, String> parameters = new HashMap<String, String>(); String contentType = HttpFields.valueParameters(req.getContentType(), parameters); if ("text/plain".equals(contentType)) { String content = IOUtils.toString(req.getInputStream(), parameters.get("charset")); int rscId = Integer.valueOf(target.substring(target.lastIndexOf("/") + 1)); return server.send(client, new WriteRequest(target, new LwM2mResource(rscId, Value.newStringValue(content)), ContentFormat.TEXT, true), TIMEOUT); } else if ("application/json".equals(contentType)) { String content = IOUtils.toString(req.getInputStream(), parameters.get("charset")); LwM2mNode node = null; try { node = gson.fromJson(content, LwM2mNode.class); } catch (JsonSyntaxException e) { throw new IllegalArgumentException("unable to parse json to tlv:" + e.getMessage(), e); } return server.send(client, new WriteRequest(target, node, null, true), TIMEOUT); } else { throw new IllegalArgumentException( "content type " + req.getContentType() + " not supported for write requests"); } } // TODO refactor the code to remove this method. private LwM2mResponse createRequest(Client client, String target, HttpServletRequest req, HttpServletResponse resp) throws IOException { Map<String, String> parameters = new HashMap<String, String>(); String contentType = HttpFields.valueParameters(req.getContentType(), parameters); if ("application/json".equals(contentType)) { String content = IOUtils.toString(req.getInputStream(), parameters.get("charset")); LwM2mNode node; try { node = gson.fromJson(content, LwM2mNode.class); } catch (JsonSyntaxException e) { throw new IllegalArgumentException("unable to parse json to tlv:" + e.getMessage(), e); } if (!(node instanceof LwM2mObjectInstance)) { throw new IllegalArgumentException("payload must contain an object instance"); } return server.send(client, new CreateRequest(target, ((LwM2mObjectInstance) node).getResources().values().toArray(new LwM2mResource[0]), ContentFormat.TLV), TIMEOUT); } else { throw new IllegalArgumentException( "content type " + req.getContentType() + " not supported for write requests"); } } }