gistfile1.js

        var stream = new Stream(new java.io.PipedInputStream());
        var _out = new java.io.PipedOutputStream(stream);
        var _runnable = new java.lang.Runnable({
            run: function() {
                javax.imageio.ImageIO.write(_image, options.imageType, _out);
            }
        });
        var _thread = new java.lang.Thread(_runnable);
        _thread.start();
        
        stream.forEach = function(callback, thisObj) {
            var length = 8192;
            var buffer = new ByteArray(length);
            while (true) {
                var read = stream.readInto(buffer, 0, length);
                if (read < 0) {
                    break;
                }
                buffer.length = read;
                callback.call(thisObj, buffer);
                buffer.length = length;
            }
        }