从Java byte [] - > Base64 - > Javascript ArrayBuffer - > Base64 - > Byte []

Question

I'm having trouble sending data from Java to Javascript and the reverse of that.

Ive tried this so far:

//a function I found online I use it to convert the decoded version of the java base64 byte[] to an ArrayBuffer
    function str2ab(str) {
      var buf = new ArrayBuffer(str.length*2); // 2 bytes for each char
      var bufView = new Uint16Array(buf);
      for (var i=0, strLen=str.length; i<strLen; i++) {
        bufView[i] = str.charCodeAt(i);
      }
      return buf;
    }

function ab2str(buf) {
  return String.fromCharCode.apply(null, new Uint16Array(buf));//retuns a different value than what I put into the buffer.
}

I really don't know how to go about this anymore any ideas?

Answer 1

Java

using import com.sun.org.apache.xml.internal.security.utils.Base64;

byte[] b = new byte[] { 12, 3, 4, 5, 12 , 34, 100 };
String encoded = Base64.encode(b);

produces:

"DAMEBQwiZA=="

JavaScript

use atob and btoa

var stringToByteArray = function(str) {
    var bytes = [];
    for (var i = 0; i < str.length; ++i) {
        bytes.push(str.charCodeAt(i));
    }
    return bytes;
};
var decoded = stringToByteArray(atob("DAMEBQwiZA=="));

produces:

[ 12, 3, 4, 5, 12 , 34, 100 ]

Note: If you are doing this in NodeJS then take a look at the atob package.