org.daxplore.presenter.server.servlets.AdminPrefixServlet.java Source code

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Here is the source code for org.daxplore.presenter.server.servlets.AdminPrefixServlet.java

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/*
 *  Copyright 2012 Axel Winkler, Daniel Dunr
 * 
 *  This file is part of Daxplore Presenter.
 *
 *  Daxplore Presenter 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 2.1 of the License, or
 *  (at your option) any later version.
 *
 *  Daxplore Presenter 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 Daxplore Presenter.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.daxplore.presenter.server.servlets;

import java.io.IOException;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.jdo.PersistenceManager;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.daxplore.presenter.server.storage.DeleteData;
import org.daxplore.presenter.server.storage.PMF;
import org.daxplore.presenter.server.storage.PrefixStore;
import org.daxplore.presenter.server.throwable.BadRequestException;
import org.daxplore.presenter.server.throwable.InternalServerException;
import org.daxplore.shared.SharedResourceTools;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;

@SuppressWarnings("serial")
public class AdminPrefixServlet extends HttpServlet {
    private static final Logger logger = Logger.getLogger(AdminPrefixServlet.class.getName());

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) {
        PersistenceManager pm = null;
        try {
            pm = PMF.get().getPersistenceManager();
            String responseText = "";
            String action = request.getParameter("action");
            if (action == null) {
                throw new BadRequestException("No action requested");
            }
            switch (action) {
            case "list":
                List<String> prefixes = PrefixStore.getPrefixes(pm);
                responseText = listToJson(prefixes);
                break;
            case "add":
                String prefix = request.getParameter("prefix");
                if (!SharedResourceTools.isSyntacticallyValidPrefix(prefix)) {
                    throw new BadRequestException("Not a syntactically valid prefix: '" + prefix + "'");
                }
                pm.makePersistent(new PrefixStore(prefix));
                logger.log(Level.INFO, "Added prefix to system: " + prefix);

                prefixes = PrefixStore.getPrefixes(pm);
                if (!prefixes.contains(prefix)) {
                    prefixes.add(prefix);
                }
                responseText = listToJson(prefixes);
                break;
            case "delete":
                prefix = request.getParameter("prefix");
                if (!SharedResourceTools.isSyntacticallyValidPrefix(prefix)) {
                    throw new BadRequestException("Not a syntactically valid prefix: '" + prefix + "'");
                }
                String result = DeleteData.deleteForPrefix(pm, prefix);
                logger.log(Level.INFO, result);

                prefixes = PrefixStore.getPrefixes(pm);
                prefixes.remove(prefix);
                responseText = listToJson(prefixes);
                break;
            case "metadata":
                prefix = request.getParameter("prefix");
                if (!SharedResourceTools.isSyntacticallyValidPrefix(prefix)) {
                    throw new BadRequestException("Not a syntactically valid prefix: '" + prefix + "'");
                }
                responseText = getPrefixMetadata(prefix);
                break;
            default:
                throw new BadRequestException("Invalid action '" + request.getParameter("action") + "' requested");
            }

            try {
                response.getWriter().write(responseText);
            } catch (IOException e) {
                throw new InternalServerException("Failed to write prefix list", e);
            }

        } catch (BadRequestException e) {
            logger.log(Level.WARNING, e.getMessage(), e);
            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        } catch (InternalServerException e) {
            logger.log(Level.SEVERE, e.getMessage(), e);
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        } catch (RuntimeException e) {
            logger.log(Level.SEVERE, "Unexpected exception: " + e.getMessage(), e);
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        } finally {
            if (pm != null) {
                pm.close();
            }
        }
    }

    @SuppressWarnings("unchecked")
    private static String listToJson(List<String> texts) {
        JSONArray jsonArray = new JSONArray();
        jsonArray.addAll(texts);
        jsonArray.toJSONString();
        return jsonArray.toJSONString();
    }

    @SuppressWarnings("unchecked")
    private static String getPrefixMetadata(String prefix) {
        JSONObject metaMap = new JSONObject();
        metaMap.put("prefix", prefix);

        // or figure out some relevant statistics that's equally interesting
        metaMap.put("statcount", "<TODO>"); //TODO count items or some such
        return metaMap.toJSONString();
    }

}