velocitywebflowdictionary.java

一个java写的business process management系统

/*
 * Copyright (c) 2003-2004, Alexander Greif
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Flow4J-Eclipse project nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package net.orthanc.flow4j.runtime.connectors.velocity;

import net.orthanc.flow4j.runtime.web.WebFlowDictionary;

import org.apache.velocity.context.Context;

/**
 * @author greifa
 *
 * To change the template for this generated type comment go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
public class VelocityWebFlowDictionary extends WebFlowDictionary {

	/**
	 * Looks for a key in the following containers, in the following order:
	 * <ol>
	 * <li>flow dictionary</li>
	 * <li>HTTP request</li>
	 * <li>HTTP session, if one exist</li>
	 * <li>Velocity context</li>
	 * </ol>
	 * If the dictionary contains no session, then tries to get the
	 * session from the request.
	 * @see net.orthanc.flow4j.runtime.WebFlowDictionary#containsKey(java.lang.String)
	 */
	public boolean extContainsKey(String key) {
		if (super.extContainsKey(key))
			return true;
		Context ctx =
			(Context) get(Flow4JVelocityConsts.DICT_KEY_VELOCITY_CONTEXT);

		if (ctx == null)
			return false;

		return ctx.containsKey(key);
	}

	/**
	 * Returns the value of the key in the following containers, in the following order:
	 * <ol>
	 * <li>flow dictionary</li>
	 * <li>HTTP request</li>
	 * <li>HTTP session, if one exist</li>
	 * <li>Velocity context, if one exist</li>
	 * </ol>
	 * If the dictionary contains no session, then tries to get the
	 * session from the request.
	 * @see net.orthanc.flow4j.runtime.WebFlowDictionary#get(java.lang.String)
	 */
	public Object extGet(String key)
		throws ClassCastException, NullPointerException {
		Object result;

		result = get(key);
		if (result != null)
			return result;

		Context ctx =
			(Context) get(Flow4JVelocityConsts.DICT_KEY_VELOCITY_CONTEXT);

		if (ctx == null)
			return null;

		return ctx.get(key);

	}
}