Convert Base64 String with Gwt

Question

How to convert a base64 String to byte array with Gwt client side code?

This link shows a encode decode, for base64 but not to byte[] array

https://snipt.net/tweakt/gwt-base64/

Answer 1

You have two options:

1- Use native JS methods btoa and atob, and convert the returned string to a java byte[] array:

 native String btoa(String b64) /*-{
    return btoa(b64);
 }-*/;
 ...
 byte[] result = btoa(myBase64Data).getBytes();

2- Use a pure java implementation of Base64 algorithm. You can just copy the Base64Utils.java included in the gwt-user.jar, and copy it to your client package, and use its methods:

 import my.project.namespace.client.Base64Utils;
 ...
 byte[] result = Base64Utils.fromBase64(myBase64Data);

Normally I use #1 for IE10, FF and webkit browsers, and #2 for old IE.

Answer 2

Try to use this library https://code.google.com/p/gwt-crypto

It was successful for me.