Moshi vs Gson in android

Question

I'm deciding on whether to use Moshi by square or Gson to serialize and deserialize model data.

one thing i always did not like about Gson is i think it uses reflection which can be slow on android? Does Moshi use reflection also?

What are some of the pros and cons of moshi vs Gson?

I see them as similar. take for example this statement that creates a typeAdapter:

class CardAdapter {
  @ToJson String toJson(Card card) {
    return card.rank + card.suit.name().substring(0, 1);
  }

  @FromJson Card fromJson(String card) {
    if (card.length() != 2) throw new JsonDataException("Unknown card: " + card);

    char rank = card.charAt(0);
    switch (card.charAt(1)) {
      case 'C': return new Card(rank, Suit.CLUBS);
      case 'D': return new Card(rank, Suit.DIAMONDS);
      case 'H': return new Card(rank, Suit.HEARTS);
      case 'S': return new Card(rank, Suit.SPADES);
      default: throw new JsonDataException("unknown suit: " + card);
    }
  }
}

and to use it register it just like in gson:

Moshi moshi = new Moshi.Builder()
.add(new CardAdapter())
.build();

I guess the advantages would be the annotation being used in the typeAdapter. I'm looking to find out if there are any performance gains if I switch to Moshi.

Answer 1

Moshi uses Okio to optimize a few things that Gson doesn’t.

• When reading field names, Moshi doesn’t have to allocate strings or do hash lookups.
• Moshi scans the input as a sequence of UTF-8 bytes, converting to Java chars lazily. For example, it never needs to convert integer literals to chars.

The benefits of these optimizations are particularly pronounced if you’re already using Okio streams. Users of Retrofit and OkHttp in particular benefit from Moshi.

Further discussion on the origins of Moshi are in my post, Moshi, another JSON Processor.