Java tutorial
/** * 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 com.alibaba.jstorm.utils; import java.io.IOException; import java.net.InetAddress; import java.net.ServerSocket; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Network utilis * * @author yannian * */ public class NetWorkUtils { private static Logger LOG = LoggerFactory.getLogger(NetWorkUtils.class); public static String hostname() { String hostname = null; try { hostname = InetAddress.getLocalHost().getCanonicalHostName(); } catch (UnknownHostException e) { LOG.error("local_hostname", e); } return hostname; } public static String ip() { String hostname = null; try { hostname = InetAddress.getLocalHost().getHostAddress(); } catch (UnknownHostException e) { LOG.error("local_hostname", e); } return hostname; } /** * Check whether the port is available to binding * * @param port * @return -1 means not available, others means available * @throws IOException */ public static int tryPort(int port) throws IOException { ServerSocket socket = new ServerSocket(port); int rtn = socket.getLocalPort(); socket.close(); return rtn; } /** * get one available port * * @return -1 means failed, others means one availablePort */ public static int getAvailablePort() { return availablePort(0); } /** * Check whether the port is available to binding * * @param prefered * @return -1 means not available, others means available */ public static int availablePort(int prefered) { int rtn = -1; try { rtn = tryPort(prefered); } catch (IOException e) { } return rtn; } public static String host2Ip(String host) { InetAddress address = null; try { address = InetAddress.getByName(host); } catch (UnknownHostException e) { LOG.warn("NetWorkUtil can't transfer hostname(" + host + ") to ip, return hostname", e); return host; } return address.getHostAddress(); } public static List<String> host2Ip(List<String> servers) { if (servers == null || servers.size() == 0) { return new ArrayList<String>(); } Set<String> ret = new HashSet<String>(); for (String server : servers) { if (StringUtils.isBlank(server)) { continue; } InetAddress ia; try { ia = InetAddress.getByName(server); } catch (UnknownHostException e) { // TODO Auto-generated catch block LOG.info("Fail to get address of ", server); continue; } if (ia.isLoopbackAddress() || ia.isAnyLocalAddress()) { ret.add(NetWorkUtils.ip()); } else { ret.add(ia.getHostAddress()); } } return JStormUtils.mk_list(ret); } public static String ip2Host(String ip) { InetAddress address = null; try { address = InetAddress.getByName(ip); } catch (UnknownHostException e) { LOG.warn("NetWorkUtil can't transfer ip(" + ip + ") to hostname, return ip", e); return ip; } return address.getHostName(); } public static boolean equals(String host1, String host2) { if (StringUtils.equalsIgnoreCase(host1, host2) == true) { return true; } if (host1 == null || host2 == null) { return false; } String ip1 = host2Ip(host1); String ip2 = host2Ip(host2); return StringUtils.equalsIgnoreCase(ip1, ip2); } public static void main(String[] args) { List<String> servers = new ArrayList<String>(); servers.add("localhost"); System.out.println(host2Ip(servers)); } }