queryserver/src/main/java/org/apache/phoenix/queryserver/server/ServerCustomizersFactory.java

/*
 * 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.phoenix.queryserver.server;

import java.util.Collections;
import java.util.List;

import org.apache.calcite.avatica.server.AvaticaServerConfiguration;
import org.apache.calcite.avatica.server.ServerCustomizer;
import org.apache.hadoop.conf.Configuration;
import org.eclipse.jetty.server.Server;

/**
 * Creates customizers for the underlying Avatica HTTP server.
 * Allows for fine grained control of authentication, etc.
 */
public interface ServerCustomizersFactory {
    /**
     * Creates a list of customizers that will customize the server.
     * @param conf Configuration to use
     * @param avaticaServerConfiguration to use in case custom-auth is enabled
     * @return List of server suctomizers
     */
    List<ServerCustomizer<Server>> createServerCustomizers(Configuration conf, AvaticaServerConfiguration avaticaServerConfiguration);

    /**
     * Factory that creates an empty list of customizers.
     */
    class ServerCustomizersFactoryImpl implements ServerCustomizersFactory {
        private static final List<ServerCustomizer<Server>> EMPTY_LIST = Collections.emptyList();
        @Override
        public List<ServerCustomizer<Server>> createServerCustomizers(Configuration conf,
                                                                      AvaticaServerConfiguration avaticaServerConfiguration) {
            return EMPTY_LIST;
        }
    }
}