alibaba/canal · error · IllegalArgumentException

Extension name == null

Error message

Extension name == null

What it means

Error "Extension name == null" thrown in alibaba/canal.

Source

Thrown at client-adapter/common/src/main/java/com/alibaba/otter/canal/client/adapter/support/ExtensionLoader.java:104

            loader = (ExtensionLoader<T>) EXTENSION_LOADERS.get(type);
        }
        return loader;
    }

    private ExtensionLoader(Class<?> type, String classLoaderPolicy){
        this.type = type;
        this.classLoaderPolicy = classLoaderPolicy;
    }

    /**
     * 返回指定名字的扩展
     *
     * @param name
     * @return
     */
    @SuppressWarnings("unchecked")
    public T getExtension(String name) {
        if (name == null || name.length() == 0) throw new IllegalArgumentException("Extension name == null");
        if ("true".equals(name)) {
            return getDefaultExtension();
        }
        Holder<Object> holder = cachedInstances.get(name);
        if (holder == null) {
            cachedInstances.putIfAbsent(name, new Holder<>());
            holder = cachedInstances.get(name);
        }
        Object instance = holder.get();
        if (instance == null) {
            synchronized (holder) {
                instance = holder.get();
                if (instance == null) {
                    instance = createExtension(name);
                    holder.set(instance);
                }
            }
        }

View on GitHub (pinned to 87be50e876)

Solutions

1. Provide a non-null, non-empty extension name when requesting an extension instance.
2. Check the adapter configuration (e.g. outer adapter key/name) matches a name defined in the SPI resource files.

When it happens

Trigger: Thrown at client-adapter/common/src/main/java/com/alibaba/otter/canal/client/adapter/support/ExtensionLoader.java:104 when the library encounters an invalid state.

Common situations: Extension name missing in the SPI config line. Validate each line of the extension file before parsing; skip or fail with the file and line number.

AI-assisted analysis of alibaba/canal@87be50e876 (2026-08-14). Data as JSON: /api/errors/cf23ac69cb37fbfb. Report an issue: GitHub.