AbDiskCache.java

/*
 * Copyright (C) 2012 www.amsoft.cn
 * 
 * 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.ab.cache;

import java.util.Collections;
import java.util.Map;

// TODO: Auto-generated Javadoc
/**
 * 
 * © 2012 amsoft.cn
 * 名称：AbCache.java 
 * 描述：缓存接口
 * @author 还如一梦中
 * @date 2015年4月3日 上午10:02:12
 * @version v1.0
 */
public interface AbDiskCache {
    /**
     * Retrieves an entry from the cache.
     * @param key Cache key
     * @return An {@link Entry} or null in the event of a cache miss
     */
    public Entry get(String key);

    /**
     * Adds or replaces an entry to the cache.
     * @param key Cache key
     * @param entry Data to store and metadata for cache coherency, TTL, etc.
     */
    public void put(String key, Entry entry);

    /**
     * Performs any potentially long-running actions needed to initialize the cache;
     * will be called from a worker thread.
     */
    public void initialize();


    /**
     * Removes an entry from the cache.
     * @param key Cache key
     */
    public void remove(String key);

    /**
     * Empties the cache.
     */
    public void clear();

    /**
     * 缓存数据实体.
     */
    public static class Entry {
    	
        /** 缓存数据. */
        public byte[] data;

        /** ETag. */
        public String etag;

        /** 缓存时间 总毫秒数. */
        public long serverTimeMillis;

        /** 失效日期 总毫秒数. */
        public long expiredTimeMillis;

        /** 响应头信息. */
        public Map<String, String> responseHeaders = Collections.emptyMap();

        /**
         *  是否记录已经失效.
         *
         * @return true, if is expired
         */
        public boolean isExpired() {
            return this.expiredTimeMillis < System.currentTimeMillis();
        }

    }

}