{"record":{"id":"cc2533d82fb386c7","repo":"apache/hadoop","slug":"does-not-implement","errorCode":null,"errorMessage":"{} does not implement {}","messagePattern":"(.+?) does not implement (.+?)","errorType":"validation","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java","lineNumber":2780,"sourceCode":"   * 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\n   *        <code>name</code>.\n   * @param <U> Interface class type.\n   * @return a <code>List</code> of objects implementing <code>xface</code>.\n   */\n  @SuppressWarnings(\"unchecked\")\n  public <U> List<U> getInstances(String name, Class<U> xface) {\n    List<U> ret = new ArrayList<U>();\n    Class<?>[] classes = getClasses(name);\n    for (Class<?> cl: classes) {\n      if (!xface.isAssignableFrom(cl)) {\n        throw new RuntimeException(cl + \" does not implement \" + xface);\n      }\n      ret.add((U)ReflectionUtils.newInstance(cl, this));\n    }\n    return ret;\n  }\n\n  /** \n   * Set the value of the <code>name</code> property to the name of a \n   * <code>theClass</code> implementing the given interface <code>xface</code>.\n   * \n   * An exception is thrown if <code>theClass</code> does not implement the \n   * interface <code>xface</code>. \n   * \n   * @param name property name.\n   * @param theClass property value.\n   * @param xface the interface implemented by the named class.\n   */\n  public void setClass(String name, Class<?> theClass, Class<?> xface) {","sourceCodeStart":2762,"sourceCodeEnd":2798,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java#L2762-L2798","documentation":"Error \"{} does not implement {}\" 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":["Configure a class that implements the required interface named in the message."],"exampleFix":"Implement the interface in the configured class.","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"}