com.github.lynxdb.server.common.HostnameProvider.java Source code

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Here is the source code for com.github.lynxdb.server.common.HostnameProvider.java

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/*
 * The MIT License
 *
 * Copyright 2016 cambierr.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.github.lynxdb.server.common;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 *
 * @author cambierr
 */
@Component
public class HostnameProvider {

    private static final Logger LOGGER = LoggerFactory.getLogger(HostnameProvider.class);

    private final String hostname;

    public HostnameProvider() {
        String tempHostName;

        try {
            tempHostName = InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException ex) {
            LOGGER.error("Hostname could not be determined using InetAddress method", ex);
            tempHostName = null;
        }

        if (tempHostName != null) {
            hostname = tempHostName;
            return;
        }

        try {
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(Runtime.getRuntime().exec("cat /etc/hostname").getInputStream()));
            tempHostName = reader.readLine();
        } catch (IOException ex) {
            LOGGER.error("Hostname could not be determined using /etc/hostname method", ex);
            tempHostName = null;
        }

        if (tempHostName != null) {
            hostname = tempHostName;
            return;
        }

        throw new RuntimeException("Could not determine hostname");
    }

    public String get() {
        return hostname;
    }

}