How to create a Spring Security Key for signing a JWT token?

Question

I use implementation group: 'io.jsonwebtoken', name: 'jjwt-api', version: '0.10.6' as dependency.

I would like to create a JWT token as follows:

@Value("${jwt.token.secret}")
private Key secret;

JwtToken.builder().value(Jwts.builder()
                .setClaims(createClaims(account))
                .setSubject(subject.toString())
                .setIssuedAt(Date.from(createdDateTime))
                .setExpiration(Date.from(expirationDateTime))
                .signWith(secret)
                .compact()).expiration(expirationDateTime.toString()).build()

I have used to provide a String in the application.properties and reference that key as shown above, but giving a String as a secretkey is deprecated. How should I create the Key secret?

Answer 1

Please see my answer to a similar question.

https://stackoverflow.com/a/71149603/1808417

//Generating a safe HS256 Secret key
SecretKey key = Keys.secretKeyFor(SignatureAlgorithm.HS256);
String secretString = Encoders.BASE64.encode(key.getEncoded());
logger.info("Secret key: " + secretString);