content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.kafka.connect.util;
  
  import org.apache.kafka.common.config.ConfigDef;
  import org.apache.kafka.common.utils.Utils;
  
  public class ConcreteSubClassValidator implements ConfigDef.Validator {
      private final Class<?> expectedSuperClass;
  
      private ConcreteSubClassValidator(Class<?> expectedSuperClass) {
          this.expectedSuperClass = expectedSuperClass;
      }
  
      public static ConcreteSubClassValidator forSuperClass(Class<?> expectedSuperClass) {
          return new ConcreteSubClassValidator(expectedSuperClass);
      }
  
      @Override
      public void ensureValid(String name, Object value) {
          if (value == null) {
              // The value will be null if the class couldn't be found; no point in performing follow-up validation
              return;
          }
  
          Class<?> cls = (Class<?>) value;
          Utils.ensureConcreteSubclass(expectedSuperClass, cls);
      }
  
      @Override
      public String toString() {
          return "A concrete subclass of " + expectedSuperClass.getName();
      }
  }
  