apache/seatunnel · error · IllegalArgumentException

SNMP source community must not be blank

Error message

SNMP source community must not be blank

What it means

The community string is the SNMPv1/v2c authentication token sent with every request; validate() throws when the configured 'community' option is null or blank because the agent would reject or the request would be meaningless without it.

Solutions

  1. Set the community string matching the agent's config, e.g. community = "public"
  2. Confirm the agent actually uses SNMPv2c/v1 (community-based); for SNMPv3 this connector's validation still requires community unless a different auth mode is supported
  3. Check for whitespace-only values or bad variable substitution

Example fix

// before
community = ""
// after
community = "public"
Defensive patterns

Strategy: validation

Validate before calling

String community = config.get(SnmpSourceOptions.COMMUNITY);
if (community == null || community.trim().isEmpty()) {
    throw new IllegalArgumentException("SNMP 'community' is required for v1/v2c agents");
}

Type guard

boolean hasCommunity(String community) {
    return community != null && !community.trim().isEmpty();
}

Try / catch

try {
    SnmpSourceConfig cfg = new SnmpSourceConfig(config);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("community must not be blank")) {
        // prompt for/derive the community string, e.g. default "public"
    }
    throw e;
}

Prevention

When it happens

Trigger: SnmpSourceConfig.validate() checks isBlank(community) after the constructor reads SnmpSourceOptions.COMMUNITY; fires when community is omitted, empty, or whitespace-only in the source config.

Common situations: Sanitized configs where the real community ('public' or a private one) was stripped before committing; assuming SNMPv3-style credentials (user/auth) and skipping community; copy of a v3 example used with a v2c agent that still requires community.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/87491bdb6c749be1. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-snmp/src/main/java/org/apache/seatunnel/connectors/seatunnel/snmp/config/SnmpSourceConfig.java:68

        if (isBlank(configuredHost)) {
            throw new IllegalArgumentException("SNMP source host must not be blank");
        }
        this.host = configuredHost.trim();
        this.port = config.get(SnmpSourceOptions.PORT);
        this.community = config.get(SnmpSourceOptions.COMMUNITY);
        this.oids = parseOids(config.get(SnmpSourceOptions.OIDS));
        this.timeoutMillis = config.get(SnmpSourceOptions.TIMEOUT_MILLIS);
        this.retries = config.get(SnmpSourceOptions.RETRIES);
        this.pollIntervalMillis = config.get(SnmpSourceOptions.POLL_INTERVAL_MILLIS);
        validate();
    }

    private void validate() {
        if (port < 1 || port > 65535) {
            throw new IllegalArgumentException("SNMP source port must be between 1 and 65535");
        }
        if (isBlank(community)) {
            throw new IllegalArgumentException("SNMP source community must not be blank");
        }
        if (timeoutMillis <= 0) {
            throw new IllegalArgumentException("SNMP source timeout_millis must be greater than 0");
        }
        if (retries < 0) {
            throw new IllegalArgumentException("SNMP source retries must not be negative");
        }
        if (pollIntervalMillis <= 0) {
            throw new IllegalArgumentException(
                    "SNMP source poll_interval_millis must be greater than 0");
        }
    }

    private static boolean isBlank(String value) {
        return value == null || value.trim().isEmpty();
    }

    @Override

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