helix-core/src/main/java/org/apache/helix/messaging/handling/MultiTypeMessageHandlerFactory.java

package org.apache.helix.messaging.handling;

/*
 * 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.
 */

import java.util.List;


public interface MultiTypeMessageHandlerFactory extends MessageHandlerFactory {

  List<String> getMessageTypes();

  @Override
  @Deprecated
  // TODO remove this default implementation for backward compatibility when clean up the legacy code.
  default String getMessageType() {
    List<String> types = getMessageTypes();
    if (types == null || types.isEmpty()) {
      return null;
    } else {
      return types.get(0);
    }
  }
}