/*
 * Copyright 2005-2008 Les Hazlewood
 *
 * Licensed 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.
 */
package org.jsecurity.web.attr;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * A <tt>WebAttribute</tt> is a storage mechanism for a single object accessible during a web request.
 *
 * <p>It is used to make objects associated with the transient request persistent beyond the request so that they can
 * be retrieved upon a later request.
 *
 * @author Les Hazlewood
 * @since 0.2
 */
public interface WebAttribute<T> {

    T retrieveValue( ServletRequest request, ServletResponse response );

    void storeValue( T value, ServletRequest request, ServletResponse response );

    void removeValue( ServletRequest request, ServletResponse response );
}