Using java-integration (1.3.0) crashes when trying to send a DONE message to cp-profiler

[Genereux-akotenou]

I'm trying to use cpprofiler to visualize a constraint programming exercise. My solver is in java so I thought I'd use the java integrator.
First I'm trying to draw a static graph in a standalone program that doesn't involve my solver to make sure everything works fine.

The code below crashes suddenly I tried to send only the disconnect that sends a message of type 'DONE' when I debug by converting into the message sent in string (using the method bytesToString)
I have the following table [8, 1]. And I think that's where the problem arises since according to the protocol I had to have just 1 in the first position since the message sent is of the DONE type.

Naturally I first send the size of the message encoded on 4bytes before sending the body of the message by removing the first bytes (which is 8 here). So my message gets through and I get a 'message: done' in the qt console where I run cpprofiler.
...
public class SimpleExample {
public static void main (String args[]) throws IOException {
Connector c = new Connector();
c.connect(6565);

//c.restart("{\"name\": \"minimal example\"}", -1);
//c.createNode(0, -1, -1, 2, Connector.NodeStatus.BRANCH).send();

c.disconnect();

}
}

The same problem arises for the other messages (START, NODE, ...) and when I remove the first bytes it does not work. The encoding of the messages does not seem to follow the protocol. I'm really lost and I ask for your help if I get lost in this matter. Thank you.

Here are some messages I tried to send
DONE -> [8,1]
START -> [8,2,56,255,255,255,255,255,255,255,255,255,1,82,27,123,34,110,97,109,101,34,58,32,34,109,105,110,105,109,97,108,32,101,120,97,109,112,108,101,34,125]

[Genereux-akotenou]

My SimpleExample.java

Connector c = new Connector();
c.connect(6565);

c.restart("{\"name\": \"minimal example\"}", -1);

c.disconnect();
}

My Connector.java(on part)

public void done() throws IOException {
  Node msg = Node.newBuilder()
    .setType(Node.MsgType.DONE)
    .build();
  sendOverSocket(msg);
}

private void sendOverSocket(Node msg) throws IOException {
    //COME WITH STRANGE 8 IN BYTE ARRAY START
    byte[] b = msg.toByteArray();
    //REMOVE FIRST BYTE
    byte[] msg_content = new byte[b.length-1];
    for(int i = 1; i < b.length; i++) {
      msg_content[i-1] = b[i];
    }

    //LET ENCODE MSG_CONTENT SIZE ON 4BYTES
    int msg_size = msg_content.length;
    byte[] size_buffer = new byte[4];
    for (int i = 0; i < 4; i++) {
        size_buffer[i] = (byte)(msg_size >>> (i * 8));
    }

    System.out.println("------ { DEV TRACE } ------");
    System.out.println(bytesToString(size_buffer));
    System.out.println(bytesToString(msg_content));
    System.out.println(bytesToString(b));

    clientSocket.getOutputStream().write(size_buffer);
    clientSocket.getOutputStream().write(msg_content);
}

// ---------- FOR DEBUG -----------
private int unsignedByteToInt(byte b) {
  return (int) b & 0xFF;
}

public String bytesToString(byte[] bytes) {
  StringBuilder sb = new StringBuilder(4 * bytes.length);
  sb.append("[");

  for (int i = 0; i < bytes.length; i++) {
    sb.append(this.unsignedByteToInt(bytes[i]));
    if (i + 1 < bytes.length) {
      sb.append(",");
    }
  }

  sb.append("]");
  return sb.toString();
}
//--------------------------------------

My console

Connector initialized v1.3.0

type: START
restart_id: -1
label: "{"name": "minimal example"}"

------ { DEV TRACE } ------
[41,0,0,0]
[2,56,255,255,255,255,255,255,255,255,255,1,82,27,123,34,110,97,109,101,34,58,32,34,109,105,110,105,109,97,108,32,101,120,97,109,112,108,101,34,125]
[8,2,56,255,255,255,255,255,255,255,255,255,1,82,27,123,34,110,97,109,101,34,58,32,34,109,105,110,105,109,97,108,32,101,120,97,109,112,108,101,34,125]

type: DONE

------ { DEV TRACE } ------
[1,0,0,0]
[1]
[8,1]

Connector closed