apache/seatunnel · error · IllegalArgumentException

Invalid endpoint: ${endpoint}, expected format host:port

Error message

Invalid endpoint: ${endpoint}, expected format host:port

What it means

parseHostAndPort locates the last ':' in the trimmed endpoint and requires it to have a character on both sides (separatorIndex > 0 and < length-1). If the colon is missing, leading, or trailing, it throws IllegalArgumentException with the offending endpoint and the expected host:port format.

Source

Thrown at seatunnel-edge-agent/seatunnel-edge-agent-transport/src/main/java/org/apache/seatunnel/edge/agent/transport/config/EdgeTransportEndpoints.java:49

    public static void validateFormat(String endpoint) {
        parseHostAndPort(endpoint);
    }

    /** Resolves {@code endpoint} to a socket address for {@link EdgeTransportClient}. */
    public static InetSocketAddress toSocketAddress(String endpoint) {
        HostPort hostPort = parseHostAndPort(endpoint);
        return new InetSocketAddress(hostPort.host, hostPort.port);
    }

    private static HostPort parseHostAndPort(String endpoint) {
        Objects.requireNonNull(endpoint, "endpoint");
        String trimmed = endpoint.trim();
        if (trimmed.isEmpty()) {
            throw new IllegalArgumentException("transport.endpoint must be non-empty.");
        }
        int separatorIndex = trimmed.lastIndexOf(':');
        if (separatorIndex <= 0 || separatorIndex >= trimmed.length() - 1) {
            throw new IllegalArgumentException(
                    "Invalid endpoint: " + endpoint + ", expected format host:port");
        }
        String host = trimmed.substring(0, separatorIndex);
        String portText = trimmed.substring(separatorIndex + 1);
        int port;
        try {
            port = Integer.parseInt(portText);
        } catch (NumberFormatException parseException) {
            throw new IllegalArgumentException(
                    "Invalid endpoint port in endpoint: " + endpoint, parseException);
        }
        if (port < 1 || port > 65535) {
            throw new IllegalArgumentException(
                    "transport.endpoint port must be a valid TCP port (1-65535), got: " + port);
        }
        return new HostPort(host, port);
    }

View on GitHub (pinned to cf67b549a7)

Solutions

1. Write the endpoint as host:port with both parts non-empty, e.g. "10.0.0.5:5800".
2. Strip any protocol scheme or path so only host:port remains.
3. If port is implied, state it explicitly; the parser does not apply defaults.
4. For hostnames, confirm the string has exactly the intended single colon separating host and numeric port.

Example fix

// before
transport.endpoint = "localhost"

// after
transport.endpoint = "localhost:5800"

String endpoint = cfg.getString("transport.endpoint").trim();
int idx = endpoint.lastIndexOf(':');
if (idx <= 0 || idx >= endpoint.length() - 1) {
    throw new IllegalStateException("transport.endpoint must be host:port, got: " + endpoint);
}

boolean looksLikeHostPort(String s) {
    String t = s == null ? "" : s.trim();
    int i = t.lastIndexOf(':');
    return i > 0 && i < t.length() - 1;
}

try {
    EdgeTransportEndpoints.validateFormat(endpoint);
} catch (IllegalArgumentException e) {
    LOG.error("Endpoint must be in host:port form: " + endpoint, e);
    throw e;
}

When it happens

Trigger: Calling EdgeTransportEndpoints.hostPort/validateFormat with endpoints like "localhost", ":8080", "host:", or "host:port:extra" where lastIndexOf(':') fails the position checks.

Common situations: Forgetting the port in a copied URL; including a scheme like "http://host:8080" is fine but "tcp:host" style prefixes without colon placement break; trailing colons from template concatenation; IPv6 unbracketed literals in exotic cases.

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

• Invalid endpoint: %s, expected format host:port
• Invalid endpoint port in endpoint: ${endpoint}
• UNSUPPORTED_DATA_TYPE
• UNSUPPORTED_DATA_TYPE
• The server id range should be syntax like '5400-5500', but g

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/df16b96da5d09e7d. Report an issue: GitHub.