Question

I was typing a question but finally I solved the problem and don’t wanted to toss it (and encouraged by https://blog.stackoverflow.com/2011/07/its-ok-to-ask-and-answer-your-own-questions/), and decided to share my problem-solution.

The problem is that I want to retrieve some bytes from a Java application server, that means, via a Servlet to load in a flash game for a replay feature.

There are some questions trying to solve the other way problem, that means, from as3 to a server (php, java, etc): How to send binary data from AS3 through Java to a filesystem?, How can I send a ByteArray (from Flash) and some form data to php?, Uploading bytearray via URLRequest and Pushing ByteArray to POST. I didn’t find something like what I’m sharing (correct me if I’m wrong).

Answer 1

Well, as I said in the question, I was encouraged by StackOverflow to answer and here it is:

The Servlet doGet method that gives the byte array:

protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

   MouseInput oneInput = getMouseInput(); //abstracted (I'm using google appengine)
   byte[] inputInBytes = oneInput.getInBytes();
   OutputStream o = resp.getOutputStream();
   o.write(inputInBytes);
   o.flush();
   o.close();
}

MouseInput.getInBytes method body:

   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   DataOutputStream dos = new DataOutputStream(baos);

   dos.writeInt(this.type);
   dos.writeDouble(this.localX);
   dos.writeDouble(this.localY);
   dos.writeBoolean(this.buttonDown);

   return baos.toByteArray();

My Actionscript code to receive the byte array data:

var url:String = "http://localhost:8888/input"; //servlet url
var request:URLRequest = new URLRequest(url);

//get rid of the cache issue:
var urlVariables:URLVariables = new URLVariables();
urlVariables.nocache = new Date().getTime();
request.data = urlVariables;
request.method = URLRequestMethod.GET;

var loader:URLLoader = new URLLoader();
loader.dataFormat = URLLoaderDataFormat.BINARY;

loader.addEventListener(Event.COMPLETE, function (evt:Event) {
    var loader:URLLoader = URLLoader(evt.target);

    var bytes:ByteArray = loader.data as ByteArray;
    trace(bytes); //yeah, you'll get nothing!

    //the bytes obtained from the request (see Servlet and 
    //MouseInput.getInBytes method body code above) were written in 
    //the sequence like is read here:           
    trace(bytes.readInt());
    trace(bytes.readDouble());
    trace(bytes.readDouble());
    trace(bytes.readBoolean());
}
loader.addEventListener(IOErrorEvent.IO_ERROR, function (evt:Event) {
    trace("error");
});

loader.load(request);

Well, it works! Obviously you can make some adjustments, like not using the anonymous function for better reading, but to illustrate it was ok! Now I can save some memory to a game replay feature (for debug purpose) with ByteArray instead of heavy XML that I was trying.

Hope it helped and any critics is appreciated!

Cheers