How to use hashMap cache to save data in java

The example of this article describes how java uses hashMap cache to save data. Share it with everyone for your reference, the details are as follows:

private static final HashMap<Long, XXX> sCache = new HashMap<Long, XXX>();
private static int sId = -1;
public static void initAlbumArtCache() {
  try {
    //。。。
    if (id != sId) {
      clearCache();
      sId = id;
    }
  } catch (RemoteException e) {
    e.printStackTrace();
  }
}
public static void clearCache() {
  synchronized(sCache) {
    sCache.clear();
  }
}
public static XXX getCachedXXX(long Index, BitmapDrawable defaultBitmap) {
  XXX d = null;
  synchronized(sCache) {
    d = sCache.get(Index);
  }
  if (d == null) {
    //。。。
    synchronized(sArtCache) {
      // the cache may have changed since we checked
      XXX value = sCache.get(Index);
      if (value == null) {
        sCache.put(Index, d);
      } else {
        d = value;
      }
    }
  }
  return d;
}

I hope this article will be helpful to everyone in java programming.

For more java related articles on how to use hashMap cache to save data, please pay attention to the PHP Chinese website!