ExecReadRequest.java

/**
 * C-JDBC: Clustered JDBC.
 * Copyright (C) 2002-2005 French National Institute For Research In Computer
 * Science And Control (INRIA).
 * Contact: c-jdbc@objectweb.org
 * 
 * This library 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 any later
 * version.
 * 
 * This library 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 this library; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * Initial developer(s): Emmanuel Cecchet.
 * Contributor(s): ______________________.
 */

package org.objectweb.cjdbc.controller.virtualdatabase.protocol;

import java.sql.SQLException;

import org.objectweb.cjdbc.common.i18n.Translate;
import org.objectweb.cjdbc.common.sql.SelectRequest;
import org.objectweb.cjdbc.controller.requestmanager.distributed.DistributedRequestManager;

/**
 * Execute a write request between several controllers.
 * 
 * @author <a href="mailto:Emmanuel.Cecchet@inria.fr">Emmanuel Cecchet </a>
 * @version 1.0
 */
public class ExecReadRequest extends DistributedRequest
{
  private long controllerId;

  /**
   * Creates a new <code>ExecReadRequest</code> object.
   * 
   * @param controllerId unique id of the controller that originally received
   *          this request
   * @param request select request to execute
   */
  public ExecReadRequest(long controllerId, SelectRequest request)
  {
    super(request);
    this.controllerId = controllerId;
  }

  /**
   * @see org.objectweb.cjdbc.controller.virtualdatabase.protocol.DistributedRequest#scheduleRequest(org.objectweb.cjdbc.controller.requestmanager.distributed.DistributedRequestManager)
   */
  public void scheduleRequest(DistributedRequestManager drm)
      throws SQLException
  {
    if (controllerId == drm.getControllerId())
      throw new SQLException(
          "No backends are available in the cluster to execute the query ("
              + request.getSQLShortForm(drm.getVirtualDatabase()
                  .getSQLShortFormLength()) + ")");
  }

  /**
   * @see org.objectweb.cjdbc.controller.virtualdatabase.protocol.DistributedRequest#executeScheduledRequest(org.objectweb.cjdbc.controller.requestmanager.distributed.DistributedRequestManager)
   */
  public Object executeScheduledRequest(DistributedRequestManager drm)
      throws SQLException
  {
    try
    {
      return drm.execReadRequest((SelectRequest) request);
    }
    catch (SQLException e)
    {
      drm.getLogger().warn(
          Translate.get("virtualdatabase.distributed.read.sqlexception", e
              .getMessage()), e);
      throw e;
    }
    catch (RuntimeException re)
    {
      drm.getLogger().warn(
          Translate.get("virtualdatabase.distributed.read.exception", re
              .getMessage()), re);
      throw new SQLException(re.getMessage());
    }
  }

}

---