RandomSelectLBStrategy.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.calcite.avatica.ha;

import org.apache.calcite.avatica.ConnectionConfig;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Random;

/**
 * Random Select strategy for client side load balancing.
 */
public class RandomSelectLBStrategy implements LBStrategy {
  private static final Logger LOG = LoggerFactory.getLogger(RandomSelectLBStrategy.class);
  public static final String URL_SEPERATOR_CHAR = ",";
  private final Random random = new Random();
  @Override
  public String getLbURL(ConnectionConfig config) {
    String[] urls = config.getLbURLs().split(URL_SEPERATOR_CHAR);
    String url = urls[random.nextInt(urls.length)];
    LOG.info("Selected URL:{}", url);
    return url;
  }
}