gsn.http.OutputStructureHandler.java Source code

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Here is the source code for gsn.http.OutputStructureHandler.java

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/**
* Global Sensor Networks (GSN) Source Code
* Copyright (c) 2006-2014, Ecole Polytechnique Federale de Lausanne (EPFL)
* 
* This file is part of GSN.
* 
* GSN 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.
* 
* GSN 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 GSN.  If not, see <http://www.gnu.org/licenses/>.
* 
* File: src/gsn/http/OutputStructureHandler.java
*
* @author Timotee Maret
* @author Ali Salehi
* @author Behnaz Bostanipour
* @author Sofiane Sarni
* @author Milos Stojanovic
*
*/

package gsn.http;

import gsn.Main;
import gsn.Mappings;
import gsn.beans.DataField;
import gsn.beans.VSensorConfig;

import java.io.IOException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

//import gsn.http.accesscontrol.User;
import gsn.http.ac.User;
import org.apache.commons.lang.StringEscapeUtils;
import org.slf4j.LoggerFactory;
import org.slf4j.Logger;

public class OutputStructureHandler implements RequestHandler {
    private static transient Logger logger = LoggerFactory.getLogger(OutputStructureHandler.class);

    public void handle(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.setStatus(HttpServletResponse.SC_OK);
        String vsName = request.getParameter("name");
        VSensorConfig sensorConfig = Mappings.getVSensorConfig(vsName);
        logger.info(new StringBuilder().append("Structure request for *").append(vsName).append("* received.")
                .toString());
        StringBuilder sb = new StringBuilder("<virtual-sensor name=\"").append(vsName).append("\">\n");
        sb.append(
                "<field name=\"time\" type=\"string\" description=\"The timestamp associated with the stream element\" unit=\"\"/>\n");
        for (DataField df : sensorConfig.getOutputStructure()) {
            sb.append("<field name=\"").append(df.getName()).append("\" ").append("type=\"").append(df.getType())
                    .append("\" ").append("description=\"")
                    .append(StringEscapeUtils.escapeXml(df.getDescription()));
            if (df.getUnit() != null && df.getUnit().trim().length() != 0)
                sb.append("\" ").append("unit=\"").append(df.getUnit());
            else
                sb.append("\" ").append("unit=\"").append("");
            sb.append("\" />\n");
        }
        sb.append("</virtual-sensor>");
        response.setHeader("Cache-Control", "no-store");
        response.setDateHeader("Expires", 0);
        response.setHeader("Pragma", "no-cache");
        response.getWriter().write(sb.toString());
    }

    public boolean isValid(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String vsName = request.getParameter("name");

        //Added by Behnaz
        HttpSession session = request.getSession();
        User user = (User) session.getAttribute("user");

        if (vsName == null || vsName.trim().length() == 0) {
            response.sendError(WebConstants.MISSING_VSNAME_ERROR, "The virtual sensor name is missing");
            return false;
        }
        VSensorConfig sensorConfig = Mappings.getVSensorConfig(vsName);
        if (sensorConfig == null) {
            response.sendError(WebConstants.ERROR_INVALID_VSNAME, "The specified virtual sensor doesn't exist.");
            return false;
        }

        //Added by Behnaz.
        if (user != null) // meaning, that a login session is active, otherwise we couldn't get there
            if (Main.getContainerConfig().isAcEnabled() == true) {
                if (user.hasReadAccessRight(vsName) == false && user.isAdmin() == false) // ACCESS_DENIED
                {
                    response.sendError(WebConstants.ACCESS_DENIED,
                            "Access denied to the specified virtual sensor .");
                    return false;
                }
            }

        return true;
    }

}