org.minidns.util.Base64 Maven / Gradle / Ivy
/*
* Copyright 2015-2024 the original author or authors
*
* This software is licensed under the Apache License, Version 2.0,
* the GNU Lesser General Public License version 2 or later ("LGPL")
* and the WTFPL.
* You may choose either license to govern your use of this software only
* upon the condition that you accept all of the terms of either
* the Apache License 2.0, the LGPL 2.1+ or the WTFPL.
*/
package org.minidns.util;
/**
* Very minimal Base64 encoder.
*/
public final class Base64 {
private static final String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
private static final String PADDING = "==";
/**
* Do not allow to instantiate Base64
*/
private Base64() {
}
public static String encodeToString(byte[] bytes) {
int paddingCount = (3 - (bytes.length % 3)) % 3;
byte[] padded = new byte[bytes.length + paddingCount];
System.arraycopy(bytes, 0, padded, 0, bytes.length);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < bytes.length; i += 3) {
int j = ((padded[i] & 0xff) << 16) + ((padded[i + 1] & 0xff) << 8) + (padded[i + 2] & 0xff);
sb.append(ALPHABET.charAt((j >> 18) & 0x3f)).append(ALPHABET.charAt((j >> 12) & 0x3f))
.append(ALPHABET.charAt((j >> 6) & 0x3f)).append(ALPHABET.charAt(j & 0x3f));
}
return sb.substring(0, sb.length() - paddingCount) + PADDING.substring(0, paddingCount);
}
}