com.chaosinmotion.securechat.server.commands.DropMessages.java Source code

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Here is the source code for com.chaosinmotion.securechat.server.commands.DropMessages.java

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/*   SecureChat: A secure chat system which permits secure communications 
 *  between iOS devices and a back-end server.
 *
 *   Copyright  2016 by William Edward Woody
 *
 *   This program 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.
 *
 *   This program 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 this program. If not, see <http://www.gnu.org/licenses/>
 */

package com.chaosinmotion.securechat.server.commands;

import java.io.IOException;
import java.sql.BatchUpdateException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONObject;
import com.chaosinmotion.securechat.server.commands.Login.UserInfo;
import com.chaosinmotion.securechat.server.database.Database;

public class DropMessages {
    private static class Message {
        int message;
        String checksum;
    }

    public static void processRequest(UserInfo userinfo, JSONObject requestParams)
            throws ClassNotFoundException, SQLException, IOException {
        ArrayList<Message> messages = new ArrayList<Message>();

        JSONArray a = requestParams.getJSONArray("messages");
        int i, len = a.length();
        for (i = 0; i < len; ++i) {
            JSONObject item = a.getJSONObject(i);
            Message msg = new Message();
            msg.message = item.getInt("messageid");
            msg.checksum = item.getString("checksum");
            messages.add(msg);
        }

        /*
         * Iterate through the messages, deleting each. We only delete a
         * message if message belongs to the user and the checksum matches.
         * This assumes it's our message and it was read with someone who
         * can read the message.
         * 
         * (Thus, the weird query)
         */

        Connection c = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        try {
            int count = 0;
            c = Database.get();
            ps = c.prepareStatement("DELETE FROM Messages " + "WHERE messageid IN "
                    + "    (SELECT Messages.messageid " + "     FROM Messages, Devices "
                    + "     WHERE Messages.messageid = ? " + "     AND Messages.checksum = ? "
                    + "     AND Devices.deviceid = Messages.deviceid " + "     AND Devices.userid = ?)");

            for (Message msg : messages) {
                /*
                 * Get the device ID for this device. Verify it belongs to the
                 * user specified
                 */

                ps.setInt(1, msg.message);
                ps.setString(2, msg.checksum);
                ps.setInt(3, userinfo.getUserID());
                ps.addBatch();
                ++count;
                if (count > 10240) {
                    ps.executeBatch();
                }
            }
            if (count > 0) {
                ps.executeBatch();
            }
        } catch (BatchUpdateException batch) {
            throw batch.getNextException();
        } finally {
            if (rs != null)
                rs.close();
            if (ps != null)
                ps.close();
            if (c != null)
                c.close();
        }
    }
}