how to generate jwt token in java code example

Example: generate jwt token java example

public String createToken(String username, List<Role> roles, String country) {

    Claims claims = Jwts.claims().setSubject(username);
    claims.put("auth", roles.stream().map(s -> new SimpleGrantedAuthority(s.getAuthority())).filter(Objects::nonNull).collect(Collectors.toList()));
    claims.put("Country", country);
    
    Date now = new Date();
    Date validity = new Date(now.getTime() + validityInMilliseconds);

    return Jwts.builder()//
        .setClaims(claims)//
        .setIssuedAt(now)//
        .setExpiration(validity)//
        .signWith(SignatureAlgorithm.HS256, secretKey)//
        .compact();
  }