| /* |
| * 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.geode.internal.util; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.Scanner; |
| |
| import org.apache.geode.internal.lang.SystemUtils; |
| |
| public class HostName { |
| |
| static final String COMPUTER_NAME_PROPERTY = "COMPUTERNAME"; |
| static final String HOSTNAME_PROPERTY = "HOSTNAME"; |
| |
| private static final String HOSTNAME = "hostname"; |
| private static final String START_OF_STRING = "\\A"; |
| private static final String UNKNOWN = "unknown"; |
| |
| public String determineHostName() { |
| String hostname = getHostNameFromEnv(); |
| if (isEmpty(hostname)) { |
| hostname = execHostName(); |
| } |
| assert !isEmpty(hostname); |
| return hostname; |
| } |
| |
| String execHostName() { |
| String hostname; |
| try { |
| Process process = new ProcessBuilder(HOSTNAME).start(); |
| try (InputStream stream = process.getInputStream(); |
| Scanner s = new Scanner(stream).useDelimiter(START_OF_STRING);) { |
| hostname = s.hasNext() ? s.next().trim() : UNKNOWN; |
| } |
| } catch (IOException hostnameBinaryNotFound) { |
| hostname = UNKNOWN; |
| } |
| return hostname; |
| } |
| |
| String getHostNameFromEnv() { |
| final String hostname; |
| if (SystemUtils.isWindows()) { |
| hostname = System.getenv(COMPUTER_NAME_PROPERTY); |
| } else { |
| hostname = System.getenv(HOSTNAME_PROPERTY); |
| } |
| return hostname; |
| } |
| |
| private boolean isEmpty(String value) { |
| return value == null || value.isEmpty(); |
| } |
| |
| } |