SessionAttributeInterceptor.java

/*
 * Copyright (c) 2002-2012 Alibaba Group Holding Limited.
 * All rights reserved.
 *
 * 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 com.alibaba.citrus.service.requestcontext.session;

public interface SessionAttributeInterceptor extends SessionInterceptor {
    /**
     * 从session中取得数据后，方法被调用。
     * <p>
     * 方法可以修改数据，并将修改后的值返回给调用者。
     * </p>
     */
    Object onRead(String name, Object value);

    /**
     * 将值设置到session中之前，方法被调用。
     * <p>
     * 方法返回的值，将被设置到session中。
     * </p>
     * <p>
     * 值为<code>null</code>表示将要从session中删除该条数据。
     * </p>
     * <p>
     * 假如方法抛出异常，那么没有任何值会被设入session中。
     * </p>
     */
    Object onWrite(String name, Object value);
}