Create Java Applet that save file from JavaScript data

I need a small class file (with source code) that get data from JavaScript page, and save to a file. The JavaScript need to show a Save Dialog Box (fileChooser). The data is encoded by using base64 encoding. The applet need to decode it before saving. For Example: <script type=text/javascript''> var data='VGhpcyBpcyBhbiBleGFtcGxl'; // This is 'This is sample' encoded text. [login to view URL]('yourApplet').saveFile(data); </script> I have developed an extension to Google Chrome: [login to view URL] I need an option to save the image to the user computer I want to use Java to show the "saving" dialog box. Because it is cross platform language The Java Applet, just need to show "Choose File" dialog box, and save a file on the user computer The file data, need to be set from javascript. The Java Applet also need to decode the string from base64 to real bytes.