apache/shenyu · error · NullPointerException

accessToken is null

Error message

accessToken is null

What it means

HttpClientRegisterRepository.doRegister looks up the cached access token for each admin server before sending a register request; if no token has been stored for that server URL (blank/null map entry) it deliberately throws NullPointerException. The token is normally obtained during the login/handshake phase, so a missing token means the client never authenticated with that admin node.

Solutions

1. Verify shenyu.register.http.username/password (or accessToken) config matches the admin credentials
2. Check client logs for the earlier login failure against that admin server
3. Ensure the admin server URL in serverLists is correct and reachable
4. Restart the client so the auth/login handshake re-runs before registering

Example fix

// before
shenyu:
  register:
    serverLists: http://admin1:9095,http://admin2:9095
    # credentials missing -> accessToken never populated
// after
shenyu:
  register:
    serverLists: http://admin1:9095,http://admin2:9095
    username: admin
    password: admin

String token = accessTokenMap.get(server); if (token == null || token.isBlank()) { reAuthenticate(server); }

try { repository.doRegister(dto); } catch (Exception e) { log.error("register failed, token/auth issue: {}", e.getMessage()); scheduleRetry(); }

When it happens

Trigger: doRegister invoked (via doPersistURI/doPersistApiDoc/doPersistInterface/doPersistMcpTools/closeRepository/doPersistDiscoveryConfig) before the per-server access token was populated, e.g. login failed, wrong username/password/token config, or the server entry in shenyu.register.serverLists was never contacted successfully.

Common situations: Misconfigured shenyu.register.serverLists containing an admin node that never completed login; wrong credentials in shenyu.register.http.username/password; clock/token expiry clearing the map before first register; client registration racing startup before authentication completes.

Related errors

• accessToken is null
• dynamic: result.getMessage() from…
• group param invalid
• websocket sync token is invalid
• Failed to get Swagger document, HTTP status code:

AI-assisted analysis of apache/shenyu@567142e072 (2026-09-12). Data as JSON: /api/errors/365c8f67a794abd5. Report an issue: GitHub.

Appendix: source

Thrown at shenyu-register-center/shenyu-register-client/shenyu-register-client-http/src/main/java/org/apache/shenyu/register/client/http/HttpClientRegisterRepository.java:199

    /**
     * doPersistDiscoveryConfig.
     *
     * @param discoveryConfigRegisterDTO discoveryConfigRegisterDTO
     */
    public void doPersistDiscoveryConfig(final DiscoveryConfigRegisterDTO discoveryConfigRegisterDTO) {
        doRegister(discoveryConfigRegisterDTO, Constants.DISCOVERY_CONFIG_PATH, Constants.DISCOVERY_CONFIG_TYPE);
    }

    private <T> void doRegister(final T t, final String path, final String type) {
        int i = 0;
        for (String server : serverList) {
            i++;
            String concat = server.concat(path);
            try {
                String accessToken = this.accessToken.get(server);
                if (StringUtils.isBlank(accessToken)) {
                    throw new NullPointerException("accessToken is null");
                }
                RegisterUtils.doRegister(GsonUtils.getInstance().toJson(t), concat, type, accessToken);
                // considering the situation of multiple clusters, we should continue to execute here
            } catch (Exception e) {
                LOGGER.error("Register admin url :{} is fail, will retry. cause:{}", server, e.getMessage());
                if (i == serverList.size()) {
                    throw new RuntimeException(e);
                }
            }
        }
    }

    private <T> void doHeartbeat(final T t, final String path) {
        int i = 0;
        for (String server : serverList) {
            i++;
            String concat = server.concat(path);
            try {

View on GitHub (pinned to 567142e072)