code: public static String generateAccessToken(String username) {
  		String accessToken = Jwts.builder().setIssuer(JWTUtils.ISSUER)
  				.setIssuedAt(new Date(System.currentTimeMillis()))
      	        .setExpiration(new Date(System.currentTimeMillis() + JWTUtils.ACCESS_TOKEN_EXPIRATION_MILLIS))
      	        .setSubject(username)
      	        .claim("type", TokenType.ACCESS)
      	        .signWith(SignatureAlgorithm.HS256, JWTUtils.SECRET)
      	        .compact();
  		
  		return accessToken;
  	}
docs: ~ Static methods *******************************************************************************************************************************