de.decoit.visa.http.ajax.handlers.IOToolTopoListHandler.java Source code

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Here is the source code for de.decoit.visa.http.ajax.handlers.IOToolTopoListHandler.java

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/*
 *  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.Map;
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.IOToolRequestStatus;
import de.decoit.visa.http.ajax.AJAXServer;

/**
 * This HttpHandler implementation handles requests to load the list of
 * available topologies from the IO-Tool.<br>
 * <br>
 * On success, a JSON object will be returned containing a JSON object that
 * contains the data received by the IO-Tool response (key: data) and the return
 * code and message of that response (keys: returncode and message). The return
 * code and message keys will also be present in an 'ajaxGeneral' reply.<br>
 * <br>
 * Any exception thrown during the processing of the request will cause the
 * request to fail.<br>
 * <br>
 * Possible return messages of this handler are:<br>
 * - ajaxSuccess (success)<br>
 * - ajaxGeneral (general error, see message key for details)<br>
 * - ajaxException (exception caught and no recovery attempt made)<br>
 *
 * @author Thomas Rix
 * @see AJAXServer
 * @see DefaultHandler
 */
public class IOToolTopoListHandler extends DefaultHandler {
    private static Logger log = Logger.getLogger(IOToolTopoListHandler.class.getName());

    @Override
    public void handle(HttpExchange he) throws IOException {
        log.info(he.getRequestURI().toString());

        // Create String for the response
        String response = null;

        // Any exception thrown during object creation will
        // cause failure of the AJAX request
        try {
            IOToolRequestStatus status = TEBackend.getIOConnector().requestTopologyList();

            JSONObject rv = new JSONObject();

            if (status == IOToolRequestStatus.SUCCESS) {
                rv.put("status", AJAXServer.AJAX_SUCCESS);

                Map<String, String> data = TEBackend.getIOConnector().getLastReturnData();

                JSONObject dataJSON = new JSONObject();
                if (data != null) {
                    for (Map.Entry<String, String> topoEntry : data.entrySet()) {
                        dataJSON.put(topoEntry.getKey(), topoEntry.getValue());
                    }
                }
                rv.put("data", dataJSON);
            } else if (status == IOToolRequestStatus.IOTOOL_BUSY) {
                rv.put("status", AJAXServer.AJAX_ERROR_IOTOOL_BUSY);
            } else {
                rv.put("status", AJAXServer.AJAX_ERROR_GENERAL);
            }

            rv.put("returncode", TEBackend.getIOConnector().getLastReturnCode());
            rv.put("message", TEBackend.getIOConnector().getLastReturnMsg());

            response = rv.toString();
        } catch (Throwable ex) {
            TEBackend.logException(ex, log);

            JSONObject rv = new JSONObject();
            try {
                rv.put("status", AJAXServer.AJAX_ERROR_EXCEPTION);
                rv.put("type", ex.getClass().getSimpleName());
                rv.put("message", ex.getMessage());
            } catch (JSONException exc) {
                /* Ignore */
            }

            response = rv.toString();
        }

        // Send the response
        sendResponse(he, response);
    }
}