SimpleObjectFactory.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License, version 3 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/gpl.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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.
 *
 * Copyright 2009 Pentaho Corporation.  All rights reserved. 
 * 
 */
package org.pentaho.test.platform.engine.core;

import java.util.HashMap;

import org.pentaho.platform.api.engine.IPentahoInitializer;
import org.pentaho.platform.api.engine.IPentahoObjectFactory;
import org.pentaho.platform.api.engine.IPentahoSession;
import org.pentaho.platform.api.engine.ObjectFactoryException;

@SuppressWarnings("nls")
/**
 * A very simplistic implementation of IPentahoObjectFactory which allows
 * the user to programmatically define platform objects for later instancing.
 * @author aphillips
 */
public class SimpleObjectFactory implements IPentahoObjectFactory {

  private HashMap<String, String> classnamesMap = new HashMap<String, String>();

  public <T> T get(Class<T> interfaceClass, IPentahoSession session) throws ObjectFactoryException {
    return get(interfaceClass, interfaceClass.getSimpleName(), session);
  }

  @SuppressWarnings("unchecked")
  public <T> T get(Class<T> interfaceClass, String key, IPentahoSession session) throws ObjectFactoryException {
    String classname = classnamesMap.get(key);
    try {
      Class implClass = Class.forName(classname);
      T t = (T) implClass.newInstance();
      if (t instanceof IPentahoInitializer) {
        ((IPentahoInitializer) t).init(session);
      }
      return t;
    } catch (Throwable th) {
      throw new ObjectFactoryException("Could not create instance for class " + classname, th);
    }
  }

  public Class<?> getImplementingClass(String key) {
    try {
      return Class.forName(classnamesMap.get(key));
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
      return null;
    }
  }

  public void init(String configFile, Object context) {
  }

  public boolean objectDefined(String key) {
    return classnamesMap.containsKey(key);
  }

  /**
   * Register an object for creation.
   * @param key identifying string
   * @param classname must be a fully qualified class name for a top-level or nested top-level (static inner) class
   */
  public void defineObject(String key, String classname) {
    classnamesMap.put(key, classname);
  }
}