Base64 Encoding in Squirrel
Our first program demonstrates base64 encoding and decoding. Here’s the full source code:
import java.util.Base64;
public class Base64Encoding {
public static void main(String[] args) {
// Here's the string we'll encode/decode.
String data = "abc123!?$*&()'-=@~";
// Java provides built-in support for base64 encoding/decoding.
// Here's how to encode using the standard encoder.
String sEnc = Base64.getEncoder().encodeToString(data.getBytes());
System.out.println(sEnc);
// Decoding may throw an exception, which you can catch
// if you don't already know the input to be well-formed.
try {
byte[] sDec = Base64.getDecoder().decode(sEnc);
System.out.println(new String(sDec));
} catch (IllegalArgumentException e) {
System.out.println("Decoding failed: " + e.getMessage());
}
System.out.println();
// This encodes/decodes using a URL-safe base64 format.
String uEnc = Base64.getUrlEncoder().encodeToString(data.getBytes());
System.out.println(uEnc);
try {
byte[] uDec = Base64.getUrlDecoder().decode(uEnc);
System.out.println(new String(uDec));
} catch (IllegalArgumentException e) {
System.out.println("URL-safe decoding failed: " + e.getMessage());
}
}
}
Java provides built-in support for base64 encoding/decoding through the java.util.Base64
class.
We start by defining our input string that we’ll encode and decode.
To perform standard base64 encoding, we use Base64.getEncoder().encodeToString()
. This method takes a byte array as input, so we convert our string to bytes using getBytes()
.
For decoding, we use Base64.getDecoder().decode()
. This method returns a byte array, which we then convert back to a string. Note that decoding can throw an IllegalArgumentException
if the input is not valid base64, so we wrap it in a try-catch block.
Java also supports URL-safe base64 encoding and decoding. We use Base64.getUrlEncoder()
and Base64.getUrlDecoder()
for these operations. The process is similar to standard base64, but it uses a slightly different character set that’s safe for use in URLs.
To run the program, compile and execute it:
$ javac Base64Encoding.java
$ java Base64Encoding
YWJjMTIzIT8kKiYoKSctPUB+
abc123!?$*&()'-=@~
YWJjMTIzIT8kKiYoKSctPUB-
abc123!?$*&()'-=@~
The string encodes to slightly different values with the standard and URL-safe base64 encoders (trailing +
vs -
), but they both decode to the original string as desired.
This example demonstrates how to use Java’s built-in base64 encoding and decoding capabilities, which are useful for various tasks such as encoding binary data for transmission over text-based protocols.