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.common.security.auth;
  
  import java.util.Objects;
  
  import javax.security.auth.callback.Callback;
  
  /**
   * Optional callback used for SASL mechanisms if any extensions need to be set
   * in the SASL exchange.
   */
  public class SaslExtensionsCallback implements Callback {
      private SaslExtensions extensions = SaslExtensions.empty();
  
      /**
       * Returns always non-null {@link SaslExtensions} consisting of the extension
       * names and values that are sent by the client to the server in the initial
       * client SASL authentication message. The default value is
       * {@link SaslExtensions#empty()} so that if this callback is
       * unhandled the client will see a non-null value.
       */
      public SaslExtensions extensions() {
          return extensions;
      }
  
      /**
       * Sets the SASL extensions on this callback.
       * 
       * @param extensions
       *            the mandatory extensions to set
       */
      public void extensions(SaslExtensions extensions) {
          this.extensions = Objects.requireNonNull(extensions, "extensions must not be null");
      }
  }
  