nl.tue.gale.ae.JSONServlet.java Source code

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Here is the source code for nl.tue.gale.ae.JSONServlet.java

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/*
    
   This file is part of GALE (Generic Adaptation Language and Engine).
    
GALE is free software: you can redistribute it and/or modify it under the 
terms of the GNU Lesser General Public License as published by the Free 
Software Foundation, either version 3 of the License, or (at your option) 
any later version.
    
GALE 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 for 
more details.
    
You should have received a copy of the GNU Lesser General Public License
along with GALE. If not, see <http://www.gnu.org/licenses/>.
    
 */
/**
 * JSONServlet.java
 * Last modified: $Date$
 * In revision:   $Revision$
 * Modified by:   $Author$
 *
 * Copyright (c) 2011 Eindhoven University of Technology.
 * All Rights Reserved.
 *
 * This software is proprietary information of the Eindhoven University
 * of Technology. It may be used according to the GNU LGPL license.
 */
package nl.tue.gale.ae;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;

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

import nl.tue.gale.common.cache.CacheSession;
import nl.tue.gale.common.uri.URI;
import nl.tue.gale.common.uri.URIs;
import nl.tue.gale.um.UMCache;
import nl.tue.gale.um.data.EntityValue;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.sdicons.json.model.JSONArray;
import com.sdicons.json.model.JSONObject;
import com.sdicons.json.model.JSONString;
import com.sdicons.json.model.JSONValue;
import com.sdicons.json.parser.JSONParser;

public class JSONServlet extends HttpServlet {
    private static final long serialVersionUID = 779878029189269484L;

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ApplicationContext applicationContext = WebApplicationContextUtils
                .getRequiredWebApplicationContext(getServletContext());

        UMCache um = (UMCache) applicationContext.getBean("umCache");
        CacheSession<EntityValue> session = um.openSession();
        try {
            JSONParser parser = new JSONParser(req.getInputStream());
            JSONArray array = (JSONArray) parser.nextValue();
            for (JSONValue value : array.getValue())
                addToUM((JSONObject) value, session);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            error(e, resp);
        } finally {
            if (session.isOpen())
                session.rollback();
        }
        reply("succes", resp);
    }

    private void error(Exception e, HttpServletResponse resp) {
        try {
            reply(e.toString(), resp);
        } catch (Exception ie) {
            throw new IllegalStateException("unable to send reply", ie);
        }
    }

    private void reply(String s, HttpServletResponse resp) throws IOException {
        resp.setBufferSize(8192);
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(resp.getOutputStream()));
        bw.write(s);
        bw.close();
    }

    private void addToUM(JSONObject object, CacheSession<EntityValue> session) {
        String user = ((JSONString) object.get("user")).getValue();
        String name = ((JSONString) object.get("name")).getValue();
        String value = ((JSONString) object.get("value")).getValue();
        URI uri = URIs.of("gale://" + user + "@gale.tue.nl/personal/");
        uri = uri.resolve(name).resolve("#value");
        session.put(uri, new EntityValue(uri, value));
        System.out.println("set um from json '" + uri + "': " + value);
    }
}