public void removeAccessTokenUsingRefreshToken(String refreshToken) {
    String tokenId = null;

    try {
      tokenId =
          dynamoDBTemplate.queryUnique(
              schema.getAccessTableName(),
              schema.getAccessIndexRefreshToken(), //
              Collections.singletonMap(
                  schema.getAccessColumnRefreshToken(),
                  new Condition()
                      .withAttributeValueList(new AttributeValue(extractTokenKey(refreshToken)))
                      .withComparisonOperator(ComparisonOperator.EQ)), //
              new ObjectExtractor<String>() {

                public String extract(Map<String, AttributeValue> values) {
                  return values.get(schema.getAccessColumnTokenId()).getS();
                }
              },
              schema.getAccessColumnTokenId());
    } catch (EmptyResultDataAccessException | IncorrectResultSizeDataAccessException e) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("Failed to find access token for refresh token " + refreshToken);
      }
    }

    if (tokenId == null) {
      return;
    }

    dynamoDBTemplate.delete(
        schema.getAccessTableName(),
        Collections.singletonMap(schema.getAccessColumnTokenId(), new AttributeValue(tokenId)));
  }
  public OAuth2AccessToken getAccessToken(OAuth2Authentication authentication) {
    OAuth2AccessToken accessToken = null;

    String key = authenticationKeyGenerator.extractKey(authentication);
    try {
      String accessTokenId =
          dynamoDBTemplate.queryUnique(
              schema.getAccessTableName(),
              schema.getAccessIndexAuthenticationId(), //
              Collections.singletonMap(
                  schema.getAccessColumnAuthenticationId(),
                  new Condition()
                      .withComparisonOperator(ComparisonOperator.EQ)
                      .withAttributeValueList(new AttributeValue(key))), //
              new ObjectExtractor<String>() {

                public String extract(Map<String, AttributeValue> values) {
                  return values.get(schema.getAccessColumnTokenId()).getS();
                }
              });
      accessToken =
          dynamoDBTemplate.get(
              schema.getAccessTableName(),
              Collections.singletonMap(
                  schema.getAccessColumnTokenId(), new AttributeValue(accessTokenId)),
              new ObjectExtractor<OAuth2AccessToken>() {

                public OAuth2AccessToken extract(Map<String, AttributeValue> values) {
                  return deserializeAccessToken(values.get(schema.getAccessColumnToken()).getB());
                }
              });
    } catch (EmptyResultDataAccessException | IncorrectResultSizeDataAccessException e) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("Failed to find access token for authentication " + authentication);
      }
    } catch (IllegalArgumentException e) {
      LOG.error("Could not extract access token for authentication " + authentication, e);
    }

    if (accessToken != null
        && !key.equals(
            authenticationKeyGenerator.extractKey(readAuthentication(accessToken.getValue())))) {
      // Keep the store consistent (maybe the same user is represented by this authentication but
      // the details have
      // changed)
      storeAccessToken(accessToken, authentication);
    }
    return accessToken;
  }