apache/dubbo · error · IllegalStateException

Try to get '${key}' failed, maybe because this key doesn't m

Error message

Try to get '${key}' failed, maybe because this key doesn't map to a Boolean object

What it means

Thrown by Configuration.getBoolean(key, Boolean defaultValue) when the value for key exists but cannot be converted to a Boolean. convert(Boolean.class, key, defaultValue) throws an Exception (e.g. the value is neither true nor false), which is caught and re-thrown as IllegalStateException. This is a type mismatch on a boolean-valued property, distinct from error 101 which is about missing keys.

Source

Thrown at dubbo-common/src/main/java/org/apache/dubbo/common/config/Configuration.java:105

    default boolean getBoolean(String key) {
        Boolean b = this.getBoolean(key, null);
        if (b != null) {
            return b;
        } else {
            throw new NoSuchElementException('\'' + key + "' doesn't map to an existing object");
        }
    }

    default boolean getBoolean(String key, boolean defaultValue) {
        return this.getBoolean(key, toBooleanObject(defaultValue));
    }

    default Boolean getBoolean(String key, Boolean defaultValue) {
        try {
            return convert(Boolean.class, key, defaultValue);
        } catch (Exception e) {
            throw new IllegalStateException(
                    "Try to get " + '\'' + key + "' failed, maybe because this key doesn't map to a Boolean object", e);
        }
    }

    /**
     * Gets a property from the configuration. This is the most basic get
     * method for retrieving values of properties. In a typical implementation
     * of the {@code Configuration} interface the other get methods (that
     * return specific data types) will internally make use of this method. On
     * this level variable substitution is not yet performed. The returned
     * object is an internal representation of the property value for the passed
     * in key. It is owned by the {@code Configuration} object. So a caller
     * should not modify this object. It cannot be guaranteed that this object
     * will stay constant over time (i.e. further update operations on the
     * configuration may change its internal state).
     *
     * @param key property to retrieve
     * @return the value to which this configuration maps the specified key, or

View on GitHub (pinned to 3a3043227f)

Solutions

Change the configured value to a literal true or false (case-insensitive).
If the value must be a truthy string, read it with getString(key) and map it yourself: "yes"/"1"/"on" -> true.
Check the original Exception cause chained in the IllegalStateException for the exact value that failed conversion.

Example fix

// before (in application.yml)
dubbo:
  consumer:
    check: yes

// after
dubbo:
  consumer:
    check: true

Defensive patterns

Strategy: validation

Validate before calling

String raw = configuration.getString(key);
if (raw != null && !raw.equalsIgnoreCase("true") && !raw.equalsIgnoreCase("false")) {
    // value is present but not boolean; sanitize or reject
    return defaultValue;
}

Try / catch

try {
    return configuration.getBoolean(key, defaultValue);
} catch (IllegalStateException e) {
    logger.warn("Non-boolean value for key {}, using default", key);
    return defaultValue;
}

Prevention

Only use true/false (case-insensitive) for boolean properties.
If environment provides yes/no or 1/0, map them to true/false before Dubbo reads them.
Add a config validation step in CI to catch malformed boolean values.

When it happens

Trigger: Calling configuration.getBoolean(key, defaultValue) where the resolved property value is a non-boolean string such as "yes", "1", "on", or "maybe". Dubbo's Boolean converter only accepts "true"/"false" (case-insensitive).

Common situations: Setting boolean Dubbo properties using shell-style truthy values (yes/no, on/off, 1/0) instead of Java boolean literals. Common when migrating from other frameworks or when environment variables from infrastructure tools use non-Java-boolean conventions.

Related errors

AI-assisted analysis of apache/dubbo@3a3043227f (2026-08-14). Data as JSON: /api/errors/75cd8b6d6d50958e. Report an issue: GitHub.