Kadang saya diberi potongan kode dalam sebuah bahasa, tapi ingin memakai potongan kode yang sama dalam bahasa lain. AI bisa membantu.

can you translate this code to Java
function canonicalizeRequestString(requestString) {
var canonicalizedString = requestString.replace(/[\n\r\t ]/g, “”);
return canonicalizedString;
}

function hashRequestString(requestString) {
var wordArray = CryptoJS.enc.Utf8.parse(requestString);
var hash = CryptoJS.SHA256(wordArray);
return hash;
}

Yes, here is how the code would look like in Java:

public static String canonicalizeRequestString(String requestString) {
    String canonicalizedString = requestString.replaceAll("[\n\r\t ]", "");
    return canonicalizedString;
}

public static String hashRequestString(String requestString) {
    byte[] wordArray = requestString.getBytes(StandardCharsets.UTF_8);
    MessageDigest digest = MessageDigest.getInstance("SHA-256");
    byte[] hash = digest.digest(wordArray);
    return new String(hash);
}

Note: In the Java code, the hashRequestString method uses the java.security.MessageDigest class to compute the SHA-256 hash of the request string. This is different from the original code, which uses the CryptoJS.SHA256 method from the CryptoJS library.

Di sini sekilas sudah benar, tapi kalo diperhatikan dengan seksama masih salah. Jadi saya jelaskan masalahnya

the result of hashRequestString wrong, it should return the hex encoded version of the hash

You are correct, the hashRequestString method in the Java code I provided returns the hash as a string of bytes. To return the hexadecimal representation of the hash instead, you can use the javax.xml.bind.DatatypeConverter class to convert the byte array to a hexadecimal string. Here is an updated version of the hashRequestString method that does this:

public static String hashRequestString(String requestString) {
byte[] wordArray = requestString.getBytes(StandardCharsets.UTF_8);
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hash = digest.digest(wordArray);
return DatatypeConverter.printHexBinary(hash);
}

This method will return the hexadecimal representation of the SHA-256 hash of the request string. For example, if the request string is "hello", the method will return the string "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824".

Saya tidak bilang bahwa saya tidak ingin memakai library eksternal, jadi saya klarifikasi lagi

I don’t want to depend on external library, can you implement it differently

Yes, you can use the java.math.BigInteger class to convert the byte array representing the hash to a hexadecimal string without using an external library. Here is an updated version of the hashRequestString method that does this:

public static String hashRequestString(String requestString) {
    byte[] wordArray = requestString.getBytes(StandardCharsets.UTF_8);
    MessageDigest digest = MessageDigest.getInstance("SHA-256");
    byte[] hash = digest.digest(wordArray);
    BigInteger bigInt = new BigInteger(1, hash);
    return bigInt.toString(16);
}

This method will return the same result as the previous version of the hashRequestString method, but it does not use the javax.xml.bind.DatatypeConverter class. Instead, it uses the java.math.BigInteger class to convert the byte array representing the hash to a hexadecimal string.