mml.handler.get.MMLResourceHandler.java Source code

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Here is the source code for mml.handler.get.MMLResourceHandler.java

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/*
 * This file is part of MML.
 *
 *  MML 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  MML 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 MML.  If not, see <http://www.gnu.org/licenses/>.
 *  (c) copyright Desmond Schmidt 2016
 */

package mml.handler.get;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import calliope.core.Utils;
import calliope.core.constants.JSONKeys;
import calliope.core.constants.Database;
import mml.constants.Params;
import calliope.core.database.Connection;
import calliope.core.database.Connector;
import calliope.core.exception.DbException;
import mml.exception.MMLException;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;

/**
 * Get a general resource
 * @author desmond
 */
public class MMLResourceHandler extends MMLGetHandler {
    String database;

    public MMLResourceHandler(String database) {
        this.database = database;
    }

    String getDefaultResource(String urn) throws DbException {
        Connection conn = Connector.getConnection();
        String original = new String(urn);
        String jStr = null;
        do {
            jStr = conn.getFromDb(database, urn);
            if (jStr == null) {
                if (this.database.equals(Database.CORFORM)) {
                    jStr = conn.getFromDb(database, urn + "/default");
                    if (jStr == null)
                        urn = Utils.chomp(urn);
                    else
                        break;
                } else
                    break;
            }
        } while (jStr == null);
        if (jStr == null)
            throw new DbException("Failed to find " + original);
        String bodyStr = "";
        if (jStr != null) {
            JSONObject jDoc = (JSONObject) JSONValue.parse(jStr);
            bodyStr = (String) jDoc.get(JSONKeys.BODY);
        } else
            throw new DbException("body key not found");
        return bodyStr;
    }

    void setEncoding(HttpServletRequest request) {
        String newEncoding = request.getParameter(Params.ENCODING);
        if (newEncoding != null && newEncoding.length() > 0)
            this.encoding = newEncoding;
        else
            encoding = "UTF-8";
    }

    /**
     * Handle the request
     * @param request the request
     * @param response the response
     * @param urn the remaining urn of the request
     * @throws MMLException 
     */
    public void handle(HttpServletRequest request, HttpServletResponse response, String urn) throws MMLException {
        try {
            String bodyStr = getDefaultResource(urn);
            setEncoding(request);
            response.setContentType("text/plain");
            response.setCharacterEncoding(encoding);
            response.getWriter().println(bodyStr);
        } catch (Exception e) {
            throw new MMLException(e);
        }
    }
}