### Question:
Base64 extends BaseNCodec { public Base64() { this(0); } Base64();  Base64(final boolean urlSafe);  Base64(final int lineLength);  Base64(final int lineLength, final byte[] lineSeparator);  Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe); boolean isUrlSafe(); @Deprecated static boolean isArrayByteBase64(final byte[] arrayOctet); static boolean isBase64(final byte octet); static boolean isBase64(final String base64); static boolean isBase64(final byte[] arrayOctet); static byte[] encodeBase64(final byte[] binaryData); static String encodeBase64String(final byte[] binaryData); static byte[] encodeBase64URLSafe(final byte[] binaryData); static String encodeBase64URLSafeString(final byte[] binaryData); static byte[] encodeBase64Chunked(final byte[] binaryData); static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked); static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked, final boolean urlSafe); static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked,
                                      final boolean urlSafe, final int maxResultSize); static byte[] decodeBase64(final String base64String); static byte[] decodeBase64(final byte[] base64Data); static BigInteger decodeInteger(final byte[] pArray); static byte[] encodeInteger(final BigInteger bigInt);  }### Answer:
@Test public void testBase64() { final String content = "Hello World"; String encodedContent; byte[] encodedBytes = Base64.encodeBase64(StringUtils.getBytesUtf8(content)); encodedContent = StringUtils.newStringUtf8(encodedBytes); assertEquals("encoding hello world", "SGVsbG8gV29ybGQ=", encodedContent); Base64 b64 = new Base64(BaseNCodec.MIME_CHUNK_SIZE, null); encodedBytes = b64.encode(StringUtils.getBytesUtf8(content)); encodedContent = StringUtils.newStringUtf8(encodedBytes); assertEquals("encoding hello world", "SGVsbG8gV29ybGQ=", encodedContent); b64 = new Base64(0, null); encodedBytes = b64.encode(StringUtils.getBytesUtf8(content)); encodedContent = StringUtils.newStringUtf8(encodedBytes); assertEquals("encoding hello world", "SGVsbG8gV29ybGQ=", encodedContent); final byte[] decode = b64.decode("SGVsbG{\u00e9\u00e9\u00e9\u00e9\u00e9\u00e9}8gV29ybGQ="); final String decodeString = StringUtils.newStringUtf8(decode); assertEquals("decode hello world", "Hello World", decodeString); }