ObjectCache.java :  » App » droidshop » net » kleinhenz » droidshop » system » Android Open Source

package net.kleinhenz.droidshop.system;

import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class ObjectCache
{
  protected long CACHE_TTL = 10800000; // 3 hours
  
  protected Map<Query, Entry> cache = new HashMap<Query, Entry>();
  
  protected class Query 
  {
    public String keywords = null;
    public String locale = null;
    public Query(String keywords, String locale)
    {
      this.keywords = keywords;
      this.locale = locale;
    }
    @Override
    public boolean equals(Object obj)
    {
      if (obj==null || !(obj instanceof Query))
        return false;
      else 
        return ((((Query)obj).keywords==null && keywords==null) || ((Query)obj).keywords.equals(keywords))
            && ((((Query)obj).locale==null && locale==null) || ((Query)obj).locale.equals(locale));
    }
    @Override
    public int hashCode()
    {
      return Arrays.hashCode(keywords.getBytes()) + Arrays.hashCode(locale.getBytes()); 
    }
  }
  
  protected class Entry
  {
    public Object object = null;
    public long timestamp = new Date().getTime();
    public Entry(Object object)
    {
      this.object = object;
    }
  }

  public Object getCache(String keywords, String locale)
  {
    Query query = new Query(keywords, locale);
    if (cache.containsKey(query) && cache.get(query).timestamp+CACHE_TTL<=new Date().getTime())
      cache.remove(query);
    if (cache.containsKey(query) && cache.get(query).timestamp+CACHE_TTL>new Date().getTime())
      return cache.get(query).object;
    
    return null;
  }

  public void putCache(String keywords, String locale, Object object)
  {
    Query query = new Query(keywords, locale);
    Entry entry = new Entry(object);
    cache.put(query, entry);
  }
}