package com.foxinmy.weixin4j.cache;
   
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileOutputStream;
   import java.io.IOException;
   
   import com.foxinmy.weixin4j.util.SerializationUtils;
   
  /**
   * 用File保存缓存对象
   *
   * @className FileCacheStorager
   * @author jinyu(foxinmy@gmail.com)
   * @date 2016年5月27日
   * @since JDK 1.6
   * @see
   */
  public class FileCacheStorager<T extends Cacheable> implements CacheStorager<T> {
  
  	private final File tmpdir;
  	private final String SEPARATOR = File.separator;
  
  	/**
  	 * 默认缓存路径：java.io.tmpdir
  	 */
  	public FileCacheStorager() {
  		this(System.getProperty("java.io.tmpdir"));
  	}
  
  	/**
  	 * 
  	 * @param path
  	 *            缓存文件报错
  	 */
  	public FileCacheStorager(String path) {
  		this.tmpdir = new File(String.format("%s%s%s", path, SEPARATOR, ALLKEY));
  		this.tmpdir.mkdirs();
  	}
  
  	@Override
  	public T lookup(String key) {
  		File cacheFile = new File(String.format("%s%s%s",
  				tmpdir.getAbsolutePath(), SEPARATOR, key));
  		try {
  			if (cacheFile.exists()) {
  				T cache = SerializationUtils.deserialize(new FileInputStream(
  						cacheFile));
  				if (cache.getExpires() < 0l) {
  					return cache;
  				}
  				if ((cache.getCreateTime() + cache.getExpires() - CUTMS) > System
  						.currentTimeMillis()) {
  					return cache;
  				}
  			}
  			return null;
  		} catch (IOException e) {
  			throw new RuntimeException(e);
  		}
  	}
  
  	@Override
  	public void caching(String key, T cache) {
  		try {
  			SerializationUtils.serialize(
  					cache,
  					new FileOutputStream(new File(String.format("%s%s%s",
  							tmpdir.getAbsolutePath(), SEPARATOR, key))));
  		} catch (IOException e) {
  			throw new RuntimeException(e);
  		}
  	}
  
  	@Override
  	public T evict(String key) {
  		T cache = null;
  		File cacheFile = new File(String.format("%s%s%s",
  				tmpdir.getAbsolutePath(), SEPARATOR, key));
  		try {
  			if (cacheFile.exists()) {
  				cache = SerializationUtils.deserialize(new FileInputStream(
  						cacheFile));
  				cacheFile.delete();
  			}
  		} catch (IOException e) {
  			; // ingore
  		}
  		return cache;
  	}
  
  	@Override
  	public void clear() {
  		for (File cache : tmpdir.listFiles()) {
  			cache.delete();
  		}
  	}
  }