jstorm-core/src/main/java/backtype/storm/utils/ZookeeperServerCnxnFactory.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 backtype.storm.utils;

import java.io.IOException;
import java.net.BindException;
import java.net.InetSocketAddress;

import org.apache.zookeeper.server.NIOServerCnxnFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ZookeeperServerCnxnFactory {
    private static final Logger LOG = LoggerFactory.getLogger(ZookeeperServerCnxnFactory.class);
    int _port;
    NIOServerCnxnFactory _factory;

    public ZookeeperServerCnxnFactory(int port, int maxClientCnxns) {
        // port range
        int max;
        if (port <= 0) {
            _port = 2000;
            max = 65535;
        } else {
            _port = port;
            max = port;
        }

        try {
            _factory = new NIOServerCnxnFactory();
        } catch (IOException e) {
            _port = 0;
            _factory = null;
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }

        // look for available port
        for (; _port <= max; _port++) {
            try {
                _factory.configure(new InetSocketAddress(_port), maxClientCnxns);
                LOG.debug("Zookeeper server successfully binded at port " + _port);
                break;
            } catch (BindException e1) {
            } catch (IOException e2) {
                _port = 0;
                _factory = null;
                e2.printStackTrace();
                throw new RuntimeException(e2.getMessage());
            }
        }

        if (_port > max) {
            _port = 0;
            _factory = null;
            LOG.error("Failed to find a port for Zookeeper");
            throw new RuntimeException("No port is available to launch an inprocess zookeeper.");
        }
    }

    public int port() {
        return _port;
    }

    public NIOServerCnxnFactory factory() {
        return _factory;
    }
}