With persistence or network transmission, we need a serialization framework.

XML and JSON are readable, but not so effective.  Protobuf/thrift/avro has good performance, but there is a need to write IDL and import a heavy library.

Finally, I wrote one by myself, which I named Packable.  Packable’s design and implementation take reference from Protobuf and Parcelable,  but is different from both of them.

Packable has the following advantages:

1. Fast encoding/decoding
2. Compact coding and small size
3. Easy to use, flexible
4. The code is light
5. Support multiple types
6. Support multiple compression strategies
7. Supports multiple languages and cross-platforms

Packable currently implements versions of Java, C++, C#, Objective-C, Go.

Example 

static class Data implements Packable {
    String msg;
    Item[] items;

    @Override
    public void encode(PackEncoder encoder) {
        encoder.putString(0, msg)
                .putPackableArray(1, items);
    }

    public static final PackCreator<Data> CREATOR = decoder -> {
        Data data = new Data();
        data.msg = decoder.getString(0);
        data.items = decoder.getPackableArray(1, Item.CREATOR);
        return data;
    };
}

static class Item implements Packable {
    int a;
    long b;

    Item(int a, long b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public void encode(PackEncoder encoder) {
        encoder.putInt(0, a);
        encoder.putLong(1, b);
    }

    static final PackArrayCreator<Item> CREATOR = new PackArrayCreator<Item>() {
        @Override
        public Item[] newArray(int size) {
            return new Item[size];
        }

        @Override
        public Item decode(PackDecoder decoder) {
            return new Item(
                    decoder.getInt(0),
                    decoder.getLong(1)
            );
        }
    };
}

static void test() {
    Data data = new Data();
    
    byte[] bytes = PackEncoder.marshal(data);
   
    Data data_2 = PackDecoder.unmarshal(bytes, Data.CREATOR);
}

Serialization

Deserialization

static void test2() {
    String msg = "message";
    int a = 100;
    int b = 200;

    PackEncoder encoder = new PackEncoder();
    encoder.putString(0, msg)
                .putInt(1, a)
                .putInt(2, b);
    byte[] bytes = encoder.getBytes();

    PackDecoder decoder = PackDecoder.newInstance(bytes);
    String dMsg = decoder.getString(0);
    int dA = decoder.getInt(1);
    int dB = decoder.getInt(2);
    decoder.recycle();

    boolean equal = msg.equals(dMsg) && (a == dA) && (b == dB);
    Assert.assertTrue(equal);
}

You are welcome to use it or join the project.  The project has been published to Github: https://github.com/BillyWei001/Packable