io.github.twinklekhj.ros.ws.codec.RosResponseCodec Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rosbridge Show documentation

RosBridge library for Java implementing ros bridge protocol

There is a newer version: 1.4.2

package io.github.twinklekhj.ros.ws.codec;

import io.github.twinklekhj.ros.op.RosResponse;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.eventbus.MessageCodec;
import io.vertx.core.json.JsonObject;

public class RosResponseCodec implements MessageCodec {
    @Override
    public void encodeToWire(Buffer buffer, RosResponse res) {
        String json = res.toJson();
        int length = json.getBytes().length;

        buffer.appendInt(length);
        buffer.appendString(json);
    }

    @Override
    public RosResponse decodeFromWire(int position, Buffer buffer) {
        // My custom message starting from this *position* of buffer
        int _pos = position;

        // Length of JSON
        int length = buffer.getInt(_pos);

        // Get JSON string by it`s length
        // Jump 4 because getInt() == 4 bytes
        String jsonStr = buffer.getString(_pos+=4, _pos+=length);
        JsonObject jsonObject = new JsonObject(jsonStr);

        return RosResponse.fromJsonObject(jsonObject);
    }

    @Override
    public RosResponse transform(RosResponse rosResponse) {
        return rosResponse;
    }

    @Override
    public String name() {
        return this.getClass().getSimpleName();
    }

    @Override
    public byte systemCodecID() {
        return -1;
    }
}