使用 Java/Kotlin Base64 解码器解码 JavaScript btoa() 编码的字符串

Question

I have an encoded string as follows:

S0VEQUkgUlVOQ0lUIFZSSU5FIEVOVEVSUFJJU0UgLSBLRyBTSU1QQU5HIDQgU09PSw

This was encoded using JavaScript btoa() function. This string can be correctly decoded using JavaScript atob() function. It should give the following decoded string:

KEDAI RUNCIT VRINE ENTERPRISE - KG SIMPANG 4 SOOK

Right now I'm developing Android app and I have to decode this string, I'm using the following to decode:

java.util.Base64.getDecoder().decode(encodedstring).toString();

I'm not getting the correct decoded output. Anyone knows what's the problem? Is it even possible to decode using Java?

Answer 1

decode(String) returns a byte[] , you need to convert that to a string using a String constructor and not the toString() method:

byte[] bytes = java.util.Base64.getDecoder().decode(encodedstring);
String s = new String(bytes, java.nio.charset.StandardCharsets.UTF_8);

Answer 2

It looks like you need mime decoder message

java.util.Base64.Decoder decoder = java.util.Base64.getMimeDecoder();  
// Decoding MIME encoded message  
String dStr = new String(decoder.decode(encodedstring));  
System.out.println("Decoded message: "+dStr);