var array = data.value;

file.initWithPath('C:\\temp\\temp.txt');
if (file.exists()) file.remove(true);
file.create(file.NORMAL_FILE_TYPE, 0666);

var fileStream = Cc['@mozilla.org/network/file-output-stream;1']
                  .createInstance(Ci.nsIFileOutputStream);
fileStream.init(file, 2, 0x200, false);

var binaryStream = Cc['@mozilla.org/binaryoutputstream;1']
                    .createInstance(Ci.nsIBinaryOutputStream);
binaryStream.setOutputStream(fileStream);
binaryStream.writeByteArray(array , array.length);

binaryStream.close();
fileStream.close();