languagetool-org/languagetool · error · RuntimeException

Invalid userInfo format, expected 'user:password':

Error message

Invalid userInfo format, expected 'user:password': 

What it means

PasswordAuthenticator supplies credentials for HTTP requests made to a URL that embeds user info. It splits the URL's userInfo on ':' and expects exactly 'user:password'; any other shape throws this RuntimeException, because it cannot build a PasswordAuthentication from it.

Source

Thrown at languagetool-core/src/main/java/org/languagetool/rules/patterns/PasswordAuthenticator.java:46

 * Authenticator that extracts username and password from URL, e.g.
 * from {@code http://user:password@myhost.org/path}
 * @since 2.7
 */
public class PasswordAuthenticator extends Authenticator {

  @Override
  @Nullable
  protected PasswordAuthentication getPasswordAuthentication() {
    if (getRequestingURL() == null) {
      return null;
    }
    String userInfo = getRequestingURL().getUserInfo();
    if (StringTools.isEmpty(userInfo)) {
      return null;
    }
    String[] parts = userInfo.split(":");
    if (parts.length != 2) {
      throw new RuntimeException("Invalid userInfo format, expected 'user:password': " + userInfo);
    }
    String username = parts[0];
    String password = parts[1];
    return new PasswordAuthentication(username, password.toCharArray());
  }

}

View on GitHub (pinned to 2e990059ce)

Solutions

1. Format the URL userInfo as exactly 'user:password' with a single colon
2. Percent-encode any ':' inside the password as %3A before putting it in the URL
3. If only a token is needed, use 'token' as username with an empty-ish password field ('token:x') as required by the target service
4. Pass credentials via an Authenticator subclass or request headers instead of URL userInfo

Example fix

// before
URL url = new URL("https://myuser:p@ss:word@example.com/model.zip");
// after
URL url = new URL("https://myuser:p%40ss%3Aword@example.com/model.zip");

String userInfo = url.getUserInfo();
if (userInfo != null && userInfo.split(":").length != 2) {
  throw new IllegalArgumentException("userInfo must be 'user:password'");
}

boolean hasValidUserInfo(URL url) {
  String ui = url == null ? null : url.getUserInfo();
  return ui == null || ui.split(":").length == 2;
}

try {
  connection.getInputStream();
} catch (RuntimeException e) {
  if (e.getMessage().startsWith("Invalid userInfo format")) {
    log.error("Fix URL credentials: encode ':' in password as %3A");
    throw new IOException(e);
  }
  throw e;
}

When it happens

Trigger: Java opening an HTTP connection (e.g. downloading language-model data) through a URL like https://host/path with userInfo set to something without exactly one colon — e.g. only a username, a token containing a colon-encoded password, or 'user:pass:extra'.

Common situations: Setting -Dhttp.proxyUser style credentials or embedding API tokens in URLs where the token itself contains ':' (colon must be percent-encoded as %3A), or forgetting the password part entirely.

Understand the failure class

Background: "Invalid URL" errors: why new URL(), URI.parse, and reqwest::Url reject your string — missing scheme, whitespace, and bad path format — this error's family across 39 libraries.

Related errors

• Expected Basic Authentication
• Unknown authMethod: <authParameter>
• Expected Basic Authentication
• apiKey AND password was set, set only apiKey
• With 'username' set, you also need to specify 'apiKey'

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/a4b4bf4e330bf5fc. Report an issue: GitHub.