apache/dubbo · error · UnsupportedOperationException

No instance of 'FileCacheStoreFactory' for you!

Error message

No instance of 'FileCacheStoreFactory' for you! 

What it means

Thrown from the private constructor of FileCacheStoreFactory, which is a utility class meant to be used only via its static getInstance methods. Instantiating it directly (including via reflection) is forbidden and immediately fails.

Source

Thrown at dubbo-common/src/main/java/org/apache/dubbo/common/cache/FileCacheStoreFactory.java:51

import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import static org.apache.dubbo.common.constants.CommonConstants.SystemProperty.USER_HOME;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.COMMON_CACHE_PATH_INACCESSIBLE;

/**
 * ClassLoader Level static share.
 * Prevent FileCacheStore being operated in multi-application
 */
public final class FileCacheStoreFactory {

    /**
     * Forbids instantiation.
     */
    private FileCacheStoreFactory() {
        throw new UnsupportedOperationException("No instance of 'FileCacheStoreFactory' for you! ");
    }

    private static final ErrorTypeAwareLogger logger =
            LoggerFactory.getErrorTypeAwareLogger(FileCacheStoreFactory.class);
    private static final ConcurrentMap<String, FileCacheStore> cacheMap = new ConcurrentHashMap<>();

    private static final String SUFFIX = ".dubbo.cache";
    private static final char ESCAPE_MARK = '%';
    private static final Set<Character> LEGAL_CHARACTERS = Collections.unmodifiableSet(new HashSet<Character>() {
        {
            // - $ . _ 0-9 a-z A-Z
            add('-');
            add('$');
            add('.');
            add('_');
            for (char c = '0'; c <= '9'; c++) {
                add(c);
            }

View on GitHub (pinned to 3a3043227f)

Solutions

1. Never instantiate FileCacheStoreFactory; always call FileCacheStoreFactory.getInstance(basePath, cacheName).
2. If a DI framework tries to construct it, exclude it from component scanning or mark it as a static utility.
3. For tests, mock the FileCacheStore returned by getInstance rather than the factory itself.

Example fix

// before
FileCacheStoreFactory f = new FileCacheStoreFactory();  // throws
// after
FileCacheStore cache = FileCacheStoreFactory.getInstance(null, "meta");

// Never instantiate the factory; always use the static accessor
FileCacheStore cache = FileCacheStoreFactory.getInstance(basePath, cacheName);

try {
    FileCacheStoreFactory.class.getDeclaredConstructor().setAccessible(true);
    // ... instantiation attempt
} catch (UnsupportedOperationException | ReflectiveOperationException e) {
    // factory cannot be instantiated; use getInstance instead
}

When it happens

Trigger: Code calls new FileCacheStoreFactory() directly, or reflection (Constructor.newInstance) invokes the private constructor. The constructor is private and throws, so both normal and reflective instantiation fail.

Common situations: A framework (Spring, a test util, a serialization lib) tries to instantiate the class reflectively. A developer unfamiliar with the API attempts to new it up instead of calling getInstance.

Related errors

• No instance of 'ConfigurationUtils' for you!
• create bean instance failed, type=${className}
• Expect only one but found ${size} matched constructors for t
• None matched constructor was found for type: ${type}
• No instance of 'NetUtils' for you!

AI-assisted analysis of apache/dubbo@3a3043227f (2026-08-14). Data as JSON: /api/errors/4154d8e191b0fa4b. Report an issue: GitHub.