org.energy_home.jemma.internal.ah.eh.esp.ESPServlet.java Source code

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Here is the source code for org.energy_home.jemma.internal.ah.eh.esp.ESPServlet.java

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/**
 * This file is part of JEMMA - http://jemma.energy-home.org
 * (C) Copyright 2013 Telecom Italia (http://www.telecomitalia.it)
 *
 * JEMMA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License (LGPL) version 3
 * or later as published by the Free Software Foundation, which accompanies
 * this distribution and is available at http://www.gnu.org/licenses/lgpl.html
 *
 * JEMMA 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 Lesser General Public License (LGPL) for more details.
 *
 */
package org.energy_home.jemma.internal.ah.eh.esp;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URI;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpResponse;
import org.apache.http.util.EntityUtils;
import org.energy_home.jemma.ah.eh.esp.ESPService;
import org.energy_home.jemma.utils.rest.RestClient;
import org.osgi.service.http.HttpService;
import org.osgi.service.http.NamespaceException;

public class ESPServlet extends HttpServlet {
    private static final long serialVersionUID = -615518450441731123L;

    private static final Log log = LogFactory.getLog(ESPServlet.class);

    private static final String servletUri = "/esp";
    private static final String userRegistrationUri = "/esp/registerUser";
    private static final String authTokenUriStr = "/esp/authToken";

    private static final String remoteGetRegistrationUri = "/ehproxy/getregisteruri.php";
    private static final String remoteAuthTokenUriStr = "/ehproxy/gethapsession.php";

    private String remoteHostAddr;
    private int remoteHostPort;

    private URI userRegistrationGetUri;
    private URI remoteAuthTokenUri;

    private ESPService espService;

    private static RestClient restClient;

    private void releaseRequestResources(HttpResponse response) {
        try {
            if (response != null)
                restClient.consume(response);
        } catch (Exception e) {
            log.error("releaseRequestResources: error while consuming rest client response", e);
        }
    }

    protected void service(HttpServletRequest servletRequest, HttpServletResponse servletResponse)
            throws ServletException, IOException {
        String queryString = servletRequest.getRequestURI();

        if (queryString.startsWith(userRegistrationUri)) {
            if (servletRequest.getRemoteHost().equals(remoteHostAddr)) {
                log.warn("service: registration uri is not accessible through vpn proxy");
                servletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
            } else {
                HttpResponse response = null;
                try {
                    response = restClient.get(userRegistrationGetUri);
                    String responseUri = EntityUtils.toString(response.getEntity());
                    servletResponse.sendRedirect(responseUri);
                } catch (Exception e) {
                    log.error("service: error while connecting to userRegistrationGetUri", e);
                    servletResponse.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
                } finally {
                    releaseRequestResources(response);
                }
            }
        } else if (queryString.startsWith(authTokenUriStr)) {
            HttpResponse response = null;
            PrintWriter pw = null;
            try {
                response = restClient.get(remoteAuthTokenUri);
                String token = EntityUtils.toString(response.getEntity());
                pw = servletResponse.getWriter();
                pw.println(token);
            } catch (Exception e) {
                log.error("service: error while connecting to remoteAuthTokenUri", e);
                servletResponse.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
            } finally {
                releaseRequestResources(response);
                if (pw != null)
                    try {
                        pw.close();
                    } catch (Exception e2) {
                        log.error(
                                "service: error while releasing printwriter used for connection to remoteAuthTokenUri",
                                e2);
                    }
            }
        } else {
            servletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    public void start() {
        try {
            remoteHostAddr = ESPConfiguration.getRemoteHostAddr();
            remoteHostPort = ESPConfiguration.getRemoteHostPort();
            userRegistrationGetUri = new URI("http", null, remoteHostAddr, remoteHostPort, remoteGetRegistrationUri,
                    null, null);
            remoteAuthTokenUri = new URI("http", null, remoteHostAddr, remoteHostPort, remoteAuthTokenUriStr, null,
                    null);
        } catch (Exception e) {
            log.error("start: error while initializing ESPServlet", e);
        }
        restClient = RestClient.get();
    }

    public void stop() {
        restClient.release();
        userRegistrationGetUri = null;
        remoteAuthTokenUri = null;
    }

    public void setHttpService(HttpService httpService) {
        try {
            httpService.registerServlet(servletUri, this, null, null);
        } catch (ServletException e) {
            e.printStackTrace();
        } catch (NamespaceException e) {
            e.printStackTrace();
        }

    }

    public void unsetHttpService(HttpService httpService) {
        httpService.unregister(servletUri);
    }

    public void setESPService(ESPService espService) {
        this.espService = espService;
    }

    public void unsetESPService(ESPService espService) {
        this.espService = null;
    }

}