Java tutorial
/* * Copyright (C) 2013, DECOIT GmbH * * This file is part of VISA Topology-Editor. * * VISA Topology-Editor is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by the * Free Software Foundation, either version 3 of the License, or (at your option) * any later version. * * VISA Topology-Editor is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * VISA Topology-Editor. If not, see <http://www.gnu.org/licenses/>. */ package de.decoit.visa.http.ajax.handlers; import java.io.IOException; import java.util.List; import org.apache.log4j.Logger; import org.json.JSONException; import org.json.JSONObject; import com.sun.net.httpserver.HttpExchange; import de.decoit.visa.TEBackend; import de.decoit.visa.enums.ModificationTarget; import de.decoit.visa.enums.ModificationTargetAttribute; import de.decoit.visa.enums.PortOrientation; import de.decoit.visa.http.QueryString; import de.decoit.visa.http.ajax.AJAXServer; import de.decoit.visa.http.ajax.ModificationQueue; import de.decoit.visa.http.ajax.ModificationQueue.Modification; import de.decoit.visa.net.IPAddress; import de.decoit.visa.net.IPNetwork; import de.decoit.visa.topology.NetworkComponent; import de.decoit.visa.topology.NetworkComponent.Interface; import de.decoit.visa.topology.NetworkComponent.Interface.IPConfig; /** * This HttpHandler implementation executes all * {@link de.decoit.visa.http.ajax.ModificationQueue.Modification Modifications} * stored in the specified {@link de.decoit.visa.http.ajax.ModificationQueue * ModificationQueue}.<br> * <br> * On success, a JSON object will be returned containing the JSON object of the * current topology (key: topology)<br> * <br> * Any exception thrown during the processing of the request will cause the * request to fail. One attempt to recover the topology from the exception is * made. If that fails, the topology and RDF model will be cleared.<br> * <br> * Possible return messages of this handler are:<br> * - ajaxSuccess (success)<br> * - ajaxException (exception caught but recovered)<br> * - ajaxExceptionUnresolved (exception caught and recovery not possible)<br> * - ajaxMissing (missing arguments) * * @author Thomas Rix * @see AJAXServer * @see DefaultHandler */ public class ExecuteModificationsHandler extends DefaultHandler { private static Logger log = Logger.getLogger(ExecuteModificationsHandler.class.getName()); @Override public void handle(HttpExchange he) throws IOException { log.info(he.getRequestURI().toString()); // Get the URI of the request and extract the query string from it QueryString queryParameters = new QueryString(he.getRequestURI()); // Create StringBuilder for the response String response = null; // Check if the query parameters are valid for this handler if (this.checkQueryParameters(queryParameters)) { // Any exception thrown during object creation will cause // failure of the AJAX request try { JSONObject rv = new JSONObject(); // Get the modification queue which will be processed ModificationQueue mq = TEBackend.getModificationQueue(queryParameters.get("queueID").get()); for (Modification mod : mq.getModifications()) { switch (mod.getTargetType()) { case COMPONENT: // Get the target object NetworkComponent nc = TEBackend.TOPOLOGY_STORAGE.getComponent(mod.getTargetLocalName()); if (mod.getTargetAttribute().equals(ModificationTargetAttribute.COMPONENT_NAME)) { nc.setName(mod.getTargetAttributeValue()); } else { throw new IllegalArgumentException( "Unsupported target attribute for target object COMPONENT found"); } break; case INTERFACE: // Get the target object Interface iface = TEBackend.TOPOLOGY_STORAGE.getInterface(mod.getTargetLocalName()); if (mod.getTargetAttribute().equals(ModificationTargetAttribute.INTERFACE_NETWORK)) { List<IPConfig> ipList = iface.getNonLinkLocalIPConfig(); if (ipList.size() > 1) { throw new UnsupportedOperationException( "Changing network value on interfaces with multiple non-link-local addresses is not supported"); } else if (ipList.size() == 1) { iface.removeIPConfiguration(ipList.get(0)); } if (!mod.getTargetAttributeValue().equals("none")) { IPNetwork network = TEBackend.TOPOLOGY_STORAGE .getNetwork(mod.getTargetAttributeValue()); IPAddress dummyAddr = network.getFreeIPAddress(); iface.configureIP(dummyAddr, network); } } else if (mod.getTargetAttribute() .equals(ModificationTargetAttribute.INTERFACE_ORIENTATION)) { PortOrientation ori = PortOrientation.valueOf(mod.getTargetAttributeValue()); iface.setOrientation(ori); } else { throw new IllegalArgumentException( "Unsupported target attribute for target object INTERFACE found"); } break; default: throw new EnumConstantNotPresentException(ModificationTarget.class, mod.getTargetType().toString()); } } rv.put("status", AJAXServer.AJAX_SUCCESS); rv.put("topology", TEBackend.TOPOLOGY_STORAGE.genTopologyJSON()); response = rv.toString(); } catch (Throwable ex) { TEBackend.logException(ex, log); try { // Synchronize the topology with the RDF model to resolve // any errors caused by the caught exception TEBackend.RDF_MANAGER.syncTopologyToRDF(); JSONObject rv = new JSONObject(); rv.put("status", AJAXServer.AJAX_ERROR_EXCEPTION); rv.put("type", ex.getClass().getSimpleName()); rv.put("message", ex.getMessage()); rv.put("topology", TEBackend.TOPOLOGY_STORAGE.genTopologyJSON()); response = rv.toString(); } catch (Throwable e) { // Exception during synchronization, the model may have been // corrupted so the whole backend was cleared JSONObject rv = new JSONObject(); try { rv.put("status", AJAXServer.AJAX_ERROR_EXCEPTION_UNRESOLVED); rv.put("topology", TEBackend.TOPOLOGY_STORAGE.genTopologyJSON()); } catch (JSONException exc) { /* Ignore */ } response = rv.toString(); } } } else { // Missing or malformed query string, set response to error code JSONObject rv = new JSONObject(); try { rv.put("status", AJAXServer.AJAX_ERROR_MISSING_ARGS); } catch (JSONException exc) { /* Ignore */ } response = rv.toString(); } // Send the response sendResponse(he, response); } /** * Check if the provided QueryString object contains all keys required by * this handler and if their values are valid. * * @param pQueryString A QueryString object with all query parameters of the * request * @return true if no problems were found, false if something is missing or * malformed */ private boolean checkQueryParameters(QueryString pQueryString) { boolean rv = true; if (rv && (!pQueryString.containsKey("queueID") || pQueryString.get("queueID").get().isEmpty())) { rv = false; } return rv; } }