title: Json Web Token issuer validation not working
body: <p>I'm doing something very very basic with JWT - Im following the tutorial <a href="https://www.baeldung.com/java-json-web-tokens-jjwt" rel="nofollow noreferrer">here</a>. I'm using the JWT library here <a href="https://github.com/jwtk/jjwt" rel="nofollow noreferrer">https://github.com/jwtk/jjwt</a></p>
  
  <p>Code is:</p>
  
  <pre><code>    final Claims claims = new DefaultClaims()
              .setExpiration(new Date(LocalDateTime.now().plus(60, DAYS).toEpochSecond(UTC) * 1000));
  
      Map&lt;String, String&gt; extraInfo = ImmutableMap.of("admin", "true");
      claims.putAll(extraInfo);
  
      String jwt = Jwts.builder().setIssuer("mycompany").setClaims(claims).signWith(HS512, secretKey).compact();
  
      Jwts.parser()
              .requireIssuer("mycompany")
              .require("admin", "true")
              .setSigningKey(secretKey)
              .parseClaimsJws(jwt);
  </code></pre>
  
  <p>Somehow, the <code>.requireIssuer("mycompany")</code> line leads to <code>MissingClaimException</code> error <code>Expected iss claim to be: mycompany, but was not present in the JWT claims.</code></p>
  
  <p>If I remove this check, the check for <code>admin: true</code> is fine. How could the issuer check possibly fail?</p>