Easy way to generate jwt token and integrate it with your java or android project - beingcoders

Generate JWT Tokens

import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.security.Key;
import io.jsonwebtoken.*;
import java.util.Date;    
 
//Sample method to construct a JWT
private String generateJWT(String id, String issuer, String subject, long ttlMillis) {
 
    //The JWT signature algorithm we will be using to sign the token
    SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;
 
    long nowMillis = System.currentTimeMillis();
    Date now = new Date(nowMillis);
 
    //We will sign our JWT with our ApiKey secret
    byte[] apiKeySecretBytes = DatatypeConverter.parseBase64Binary(apiKey.getSecret());
    Key signingKey = new SecretKeySpec(apiKeySecretBytes, signatureAlgorithm.getJcaName());
 
    //Let's set the JWT Claims
    JwtBuilder builder = Jwts.builder().setId(id)
                                .setIssuedAt(now)
                                .setSubject(subject)
                                .setIssuer(issuer)
                                .signWith(signatureAlgorithm, signingKey);
 
    //if it has been specified, let's add the expiration
    if (ttlMillis >= 0) {
    long expMillis = nowMillis + ttlMillis;
        Date exp = new Date(expMillis);
        builder.setExpiration(exp);
    }
 
    //Builds the JWT and serializes it to a compact, URL-safe string
    return builder.compact();
}

Hello, this is really great and helpful. I was wondering what is meant by apikey.getSecret()
I don't see any variable listed named apiKey. Is this just a placeholder for "somehow read your .pem file for the secret/private key?"

@DavisNicholas04 , Yes you are absolutely right. If you are using Spring or Spring Boot, you can use @propertysource annotation to read your application configurations. Or you can simply retrieve it from your database tables.

Depending on your security level and project architecture - You can implement your own logic to retrieve the values!