mybatis/mybatis-3 · error · ExecutorException

Cannot get Configuration as configuration factory was not se

Error message

Cannot get Configuration as configuration factory was not set.

What it means

Thrown when MyBatis must rebuild the lazy-loading machinery of a deserialized object but the configurationFactory was never set. Because LoadPair is serialized without the live Configuration, the only way to get it back is a user-supplied factory class; if lazyLoadingEnabled is true but configurationFactory is omitted in the mybatis-config settings, this fails.

Source

Thrown at src/main/java/org/apache/ibatis/executor/loader/ResultLoaderMap.java:227

            metaResultObject.getSetterType(this.property), null, null);
      }

      /*
       * We are using a new executor because we may be (and likely are) on a new thread and executors aren't thread
       * safe. (Is this sufficient?) A better approach would be making executors thread safe.
       */
      if (this.serializationCheck == null) {
        final ResultLoader old = this.resultLoader;
        this.resultLoader = new ResultLoader(old.configuration, new ClosedExecutor(), old.mappedStatement,
            old.parameterObject, old.targetType, old.cacheKey, old.boundSql);
      }

      this.metaResultObject.setValue(property, this.resultLoader.loadResult());
    }

    private Configuration getConfiguration() {
      if (this.configurationFactory == null) {
        throw new ExecutorException("Cannot get Configuration as configuration factory was not set.");
      }

      Object configurationObject;
      try {
        final Method factoryMethod = this.configurationFactory.getDeclaredMethod(FACTORY_METHOD);
        if (!Modifier.isStatic(factoryMethod.getModifiers())) {
          throw new ExecutorException("Cannot get Configuration as factory method [" + this.configurationFactory + "]#["
              + FACTORY_METHOD + "] is not static.");
        }

        if (!factoryMethod.canAccess(null)) {
          configurationObject = AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () -> {
            try {
              factoryMethod.setAccessible(true);
              return factoryMethod.invoke(null);
            } finally {
              factoryMethod.setAccessible(false);
            }

View on GitHub (pinned to 008069adb1)

Solutions

Add <setting name="configurationFactory" value="com.example.MyConfigFactory"/> to the <settings> block of mybatis-config.xml
Ensure the factory class has a public static Configuration getConfiguration() method returning the live SqlSessionFactory's Configuration
Pre-load lazy properties before serialization so no Configuration rebuild is needed
Make the statement parameter object Serializable so the LoadPair actually records the factory at build time

Example fix

<!-- before -->
<settings>
  <setting name="lazyLoadingEnabled" value="true"/>
</settings>
<!-- after -->
<settings>
  <setting name="lazyLoadingEnabled" value="true"/>
  <setting name="configurationFactory" value="com.example.MyBatisConfigFactory"/>
</settings>

Defensive patterns

Strategy: validation

Validate before calling

// At startup, fail fast if lazy loading is on but the factory is unset
Configuration cfg = sqlSessionFactory.getConfiguration();
if (cfg.isLazyLoadingEnabled() && cfg.getConfigurationFactory() == null) {
  throw new IllegalStateException("Set configurationFactory when lazyLoadingEnabled=true");
}

Try / catch

try { lazyObj.getLazyProp(); } catch (ExecutorException e) { if (e.getMessage().contains("configuration factory was not set")) { log.error("Config error: add configurationFactory setting", e); } throw e; }

Prevention

Treat lazyLoadingEnabled and configurationFactory as one unit in config reviews
Add a startup assertion for the settings pair
Document the factory convention in the project's config template

When it happens

Trigger: A deserialized lazy-loading proxy has load(userObject) called (metaResultObject/resultLoader null), mappedParameter non-null, and LoadPair.getConfiguration() finds this.configurationFactory == null, i.e. <setting name='lazyLoadingEnabled' value='true'/> without <setting name='configurationFactory' value='...'/>.

Common situations: Enabling lazy loading for serializable result objects (session replication, distributed caches) but forgetting the configurationFactory setting; configurationFactory silently not serialized because the parameter object was not Serializable so the field was never populated.

Related errors

AI-assisted analysis of mybatis/mybatis-3@008069adb1 (2026-08-14). Data as JSON: /api/errors/ff68aa6aebcee81c. Report an issue: GitHub.