{"record":{"id":"d8c860c27af0cab4","repo":"apache/hadoop","slug":"not","errorCode":null,"errorMessage":"{} not {}","messagePattern":"\\{\\} not \\{\\}","errorType":"validation","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java","lineNumber":2751,"sourceCode":"   * returned.\n   * \n   * An exception is thrown if the returned class does not implement the named\n   * interface. \n   * \n   * @param name the conf key name.\n   * @param defaultValue default value.\n   * @param xface the interface implemented by the named class.\n   * @param <U> Interface class type.\n   * @return property value as a <code>Class</code>, \n   *         or <code>defaultValue</code>.\n   */\n  public <U> Class<? extends U> getClass(String name, \n                                         Class<? extends U> defaultValue, \n                                         Class<U> xface) {\n    try {\n      Class<?> theClass = getClass(name, defaultValue);\n      if (theClass != null && !xface.isAssignableFrom(theClass))\n        throw new RuntimeException(theClass+\" not \"+xface.getName());\n      else if (theClass != null)\n        return theClass.asSubclass(xface);\n      else\n        return null;\n    } catch (Exception e) {\n      throw new RuntimeException(e);\n    }\n  }\n\n  /**\n   * Get the value of the <code>name</code> property as a <code>List</code>\n   * of objects implementing the interface specified by <code>xface</code>.\n   * \n   * An exception is thrown if any of the classes does not exist, or if it does\n   * not implement the named interface.\n   * \n   * @param name the property name.\n   * @param xface the interface implemented by the classes named by","sourceCodeStart":2733,"sourceCodeEnd":2769,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java#L2733-L2769","documentation":"Error \"{} not {}\" thrown in apache/hadoop.","triggerScenarios":"Raised at runtime when the documented precondition or configuration requirement for this operation is violated.","commonSituations":"Misconfigured or missing property, invalid user input, or calling the API before its prerequisites are met.","solutions":["The configured class is not of the expected type; configure a class of the required interface."],"exampleFix":"Use a class implementing the expected interface.","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-22T20:17:22.307Z"}