Groovy: regex & Base64

regexJava.groovy

#!/usr/bin/env groovy 

import java.util.Base64
import java.util.Base64.Decoder
import java.util.Base64.Encoder
import java.util.regex.Matcher
import java.util.regex.Pattern
import java.nio.charset.StandardCharsets;

final Decoder decoder = Base64.getDecoder()
String bytesEncoded = Base64.getEncoder().encodeToString("a test message to encode".getBytes( StandardCharsets.UTF_8 ) )

String line = "=[" + bytesEncoded + "]"
println "value before regex: ${line}"

Pattern r = Pattern.compile( "=\\[(.*)\\]" )
Matcher m = r.matcher( line )
if ( m.find( ) ) {

	String tmp = m.group( 1 )
	println "value after rexex find: ${tmp}"

    byte[] decodedTmp = decoder.decode( tmp )
	def val = new String(decodedTmp, StandardCharsets.UTF_8);
    println "value after decoding: ${val}"
}