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.cassandra.sidecar.common.server.dns;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  
  import com.fasterxml.jackson.annotation.JsonProperty;
  
  /**
   * Determines which DnsResolver to use. Currently supported implementations are
   * default and resolve_to_ip. The former will resolve hostname to address and
   * address to hostname whereas the latter will only resolve hostname to address.
   */
  public enum DnsResolvers implements DnsResolver
  {
      /**
       * Default implementation of the {@link DnsResolver} that uses the JDK's
       * underlying DNS resolution mechanism
       */
      @JsonProperty("default")
      DEFAULT
      {
          /**
           * {@inheritDoc}
           */
          @Override
          public String reverseResolve(String address) throws UnknownHostException
          {
              return InetAddress.getByName(address).getHostName();
          }
      },
  
      /**
       * Implementation of the {@link DnsResolver} interface that always resolves
       * and reverse resolves to an IP address
       */
      @JsonProperty("resolve_to_ip")
      RESOLVE_TO_IP
      {
          /**
           * Returns the hostAddress for the provided address
           *
           * @param address IP address
           * @return IP address
           * @throws UnknownHostException when the host is not known
           */
          @Override
          public String reverseResolve(String address) throws UnknownHostException
          {
              return InetAddress.getByName(address).getHostAddress();
          }
      };
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String resolve(String hostname) throws UnknownHostException
      {
             return InetAddress.getByName(hostname).getHostAddress();
      }
  }
  