🔧Utility Class

Class features

• All methods are static (no instantiation needed)

• Encode/decode for URL, Base64, CSV, JSON, XML and YAML

• AES256 encrypt/decrypt (AES/CBC/PKCS5Padding). The passed secure key is first hashed using SHA-256 to form a 256-bit key. You may use K.getRandomBytes(16) to generate the required initialization vector

• ZLIB compress/decompress

• Generate hash (MD5, SHA-2 or SHA-3)

• Query any DNS record (MX, A, etc.). The MX records are returned in priority order

• Delay thread

• Get various environment information (JVM version, IP address, hostname, etc.)

Example Delay Thread

// Wait 1/4 second
K.waitMilliseconds(250);

// Wait 5 minutes
K.waitMinutes(5);

Example Encode/Decode

// Encode Base-64 string
String httpAuth = K.encodeBase64(userName + ':' + password);

// Encode URL
String urlEncoded = K.encodeURL("https://example.com?q=1&p=done");

Example Query DNS Server

// Get DNS SOA record
String[] soaRRs = K.queryDNS("SOA", "google.com");

// Get DNS MX record(s)
String[] mxRRs = K.queryDNS("MX", "yahoo.com");

Example AES-256

String secretKey = "This is the secret key";
		
// Create a simple text file
KFile.writeFile("This is a simple text file", "AES-Text.txt");
		
// Generate and save random AES-256 initialization vector
KFile.writeFile(K.getRandomBytes(16), "AES.iv");
		
// AES-256 Encrypt
byte[] clearText	= KFile.readByteFile("AES-Text.txt");
byte[] initVector	= KFile.readByteFile("AES.iv");
byte[] cipherText	= K.encryptAES256(clearText, secretKey.getBytes(), initVector);
KFile.writeFile(cipherText, "AES-Text.encrypted");
		
// AES-256 Decrypt
cipherText	= KFile.readByteFile("AES-Text.encrypted");
initVector	= KFile.readByteFile("AES.iv");
clearText	= K.decryptAES256(cipherText, secretKey.getBytes(), initVector);
		
System.out.println(new String(clearText));