/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

//
// This source code implements specifications defined by the Java
// Community Process. In order to remain compliant with the specification
// DO NOT add / change / or delete method signatures!
//

package javax.servlet.http;

/**
 * Events of this type are either sent to an object that implements
 * {@link HttpSessionBindingListener} when it is bound or
 * unbound from a session, or to a {@link HttpSessionAttributeListener}
 * that has been configured in the deployment descriptor when any attribute is
 * bound, unbound or replaced in a session.
 *
 * <p>The session binds the object by a call to
 * <code>HttpSession.setAttribute</code> and unbinds the object
 * by a call to <code>HttpSession.removeAttribute</code>.
 *
 * @see HttpSession
 * @see HttpSessionBindingListener
 * @see HttpSessionAttributeListener
 *
 * @version $Rev$ $Date$
 */
public class HttpSessionBindingEvent extends HttpSessionEvent {
    /**
     *  The name to which the object is being bound or unbound
     */
    private String name;

    /**
     *  The object is being bound or unbound
     */
    private Object value;

    /**
     * Constructs an event that notifies an object that it
     * has been bound to or unbound from a session.
     * To receive the event, the object must implement
     * {@link HttpSessionBindingListener}.
     *
     * @param session the session to which the object is bound or unbound
     *
     * @param name the name with which the object is bound or unbound
     *
     * @see #getName
     * @see #getSession
     */
    public HttpSessionBindingEvent(HttpSession session, String name) {
        super(session);
        this.name = name;
    }

    /**
     * Constructs an event that notifies an object that it
     * has been bound to or unbound from a session.
     * To receive the event, the object must implement
     * {@link HttpSessionBindingListener}.
     *
     * @param session the session to which the object is bound or unbound
     *
     * @param name the name with which the object is bound or unbound
     *
     * @see #getName
     * @see #getSession
     */
    public HttpSessionBindingEvent(HttpSession session, String name, Object value) {
        super(session);
        this.name = name;
        this.value = value;
    }

    /**
     * Return the session that changed.
     */
    public HttpSession getSession() {
        return super.getSession();
    }

    /**
     * Returns the name with which the attribute is bound to or unbound from
     * the session.
     *
     * @return a string specifying the name with which the object is bound to
     * or unbound from the session
     */
    public String getName() {
        return name;
    }

    /**
     * Returns the value of the attribute that has been added, removed or
     * replaced. If the attribute was added (or bound), this is the value of
     * the attribute. If the attrubute was removed (or unbound), this is the
     * value of the removed attribute. If the attribute was replaced, this
     * is the old value of the attribute.
     *
     * @since Servlet 2.3
     */
    public Object getValue() {
        return this.value;
    }
}