com.whaleal.icefrog.cache.impl.CacheObj Maven / Gradle / Ivy

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package com.whaleal.icefrog.cache.impl;

import java.io.Serializable;
import java.util.concurrent.atomic.AtomicLong;

/**
 * 缓存对象
 *
 * @param  Key类型
 * @param  Value类型
 * @author Looly
 * @author wh
 */
public class CacheObj implements Serializable {
    private static final long serialVersionUID = 1L;

    protected final K key;
    protected final V obj;
    /**
     * 对象存活时长，0表示永久存活
     */
    private final long ttl;
    /**
     * 访问次数
     */
    protected AtomicLong accessCount = new AtomicLong();
    /**
     * 上次访问时间
     */
    private volatile long lastAccess;

    /**
     * 构造
     *
     * @param key 键
     * @param obj 值
     * @param ttl 超时时长
     */
    protected CacheObj( K key, V obj, long ttl ) {
        this.key = key;
        this.obj = obj;
        this.ttl = ttl;
        this.lastAccess = System.currentTimeMillis();
    }

    /**
     * 获取键
     *
     * @return 键
     * @since 1.0.0
     */
    public K getKey() {
        return this.key;
    }

    /**
     * 获取值
     *
     * @return 值
     * @since 1.0.0
     */
    public V getValue() {
        return this.obj;
    }

    @Override
    public String toString() {
        return "CacheObj [key=" + key + ", obj=" + obj + ", lastAccess=" + lastAccess + ", accessCount=" + accessCount + ", ttl=" + ttl + "]";
    }

    /**
     * 判断是否过期
     *
     * @return 是否过期
     */
    protected boolean isExpired() {
        if (this.ttl > 0) {
            // 此处不考虑时间回拨
            return (System.currentTimeMillis() - this.lastAccess) > this.ttl;
        }
        return false;
    }

    /**
     * 获取值
     *
     * @param isUpdateLastAccess 是否更新最后访问时间
     * @return 获得对象
     * @since 1.0.0
     */
    protected V get( boolean isUpdateLastAccess ) {
        if (isUpdateLastAccess) {
            lastAccess = System.currentTimeMillis();
        }
        accessCount.getAndIncrement();
        return this.obj;
    }
}