org.ow2.bonita.env.EnvironmentHelper Maven / Gradle / Ivy

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/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This 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.
 *
 * This software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.ow2.bonita.env;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.ow2.bonita.util.BonitaRuntimeException;
import org.ow2.bonita.util.ExceptionManager;

/**
 * @author Tom Baeyens
 */
public abstract class EnvironmentHelper {

  static Map, Object> defaultObjectCache = new HashMap, Object>();

  @SuppressWarnings("unchecked")
  public static  T get(Class type) {
    if (type == null) {
      return null;
    }
    Environment environment = Environment.getCurrent();
    if (environment != null) {
      return environment.get(type);
    }
    if (defaultObjectCache.containsKey(type)) {
      return (T) defaultObjectCache.get(type);
    }
    try {
      Method defaultFactoryMethod = type.getMethod("createDefault");
      if (defaultFactoryMethod != null) {
        Object defaultObject = defaultFactoryMethod.invoke(null);
        defaultObjectCache.put(type, defaultObject);
        return (T) defaultObject;
      }
    } catch (Exception e) {
    	String message = ExceptionManager.getInstance().getFullMessage("bp_EH_1", type.getName());
      throw new BonitaRuntimeException(message, e);
    }
    return null;
  }
}