Uploading image to server using Java Script (Nashorn) - corrupted image

[Xavier Mayeur]

Hello,


I am struggling trying to upload a PNG image to a web site, in order to publish my documentation work on a Confluence page.

I am able to do it perfectly using Python requests, but I need to use Nashorn Java Script in order to automate this image upload from a design tool


The POST actually works and the the image is uploaded (HTTP return code 200).
Unfortunately, the uploaded image binary code does not match the original file.
I suspect a character set conversion issue, but I do not succeed to solve it, being a newbie in Java Script.

I tried to force different charset setting, but without success...


Here a snippet of the code. Does it trigger some suggestion from the Community ?


Thanks


Xavier


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function httpSendImage(method, theUrl, files,  headers) {


    method = method || 'POST';


    lineEnd = "\r\n";
    twoHyphens = "--";
    boundary = "***232404jkg4220957934FW**";
   var   existingFileName='';


    maxBufferSize = 1 * 1024 * 1024;


    // Post Client request     
    try {
        var con = new java.net.URL(theUrl).openConnection();
        con.doOutput=true;
        con.doInput=true;
        con.useCaches=false;
        con.requestMethod = method;
        
        con.setRequestProperty("Connection", "Keep-Alive");
        con.setRequestProperty("Content-Type","multipart/form-data;boundary=" + boundary);
      
      var filesData ='';
      if (files != undefined) {
         for (var prop in files) {
            if (prop === 'filename') {
               existingFileName = files[prop];
               fileparts = existingFileName.split("\\");
               files[prop] = fileparts[fileparts.length-1];
            }
            filesData += prop + '=\"' +  files[prop] + '\"; ';
         }
         filesData = filesData.substring(0, filesData.length-2);
        }   


        if (headers != undefined) {
            for (var prop in headers) {
                con.setRequestProperty(prop ,headers[prop]);
            }
        }


        if (authorization != null) {con.setRequestProperty("Authorization", authorization);}


        var dos = new java.io.DataOutputStream(con.outputStream);
      var buf = Java.type('byte[]');
        dos.writeBytes(twoHyphens + boundary + lineEnd);
        dos.writeBytes("Content-Disposition: form-data; name=\"file\"; " + filesData  + "\nContent-Type: image/png; charset=utf-8" + lineEnd);
        dos.writeBytes(lineEnd);


        // write bytes into form...


      buf = readFile(existingFileName);
      // console.log('buf length: ' + buf.length);
      dos.writeBytes(buf);
        // send multipart form data necesssary after file data...

        dos.writeBytes(lineEnd);
        dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

        // close streams
        dos.flush();
        dos.close();


        return asResponse(con);


    }
    catch(err) {
        console.log("Error sending file: " + err.message);
    }