dubbo注册服务IP解析异常及IP解析源码分析

 /** * 判断host是否为不可用的本地Host */ public static boolean isInvalidLocalHost(String host) { return host == null || host.length() == 0 || host.equalsIgnoreCase("localhost") || host.equals("0.0.0.0") || (LOCAL_IP_PATTERN.matcher(host).matches()); } /** * 获取本地Host. * 若address == null ? "127.0.0.1" : InetAddress.getHostAddress(); */ public static String getLocalHost(){ InetAddress address = getLocalAddress(); return address == null ? LOCALHOST : address.getHostAddress(); } private void doExportUrlsFor1Protocol(ProtocolConfig protocolConfig, List<URL> registryURLs) { ... ... //1. 先从ProtocolConfig中取host. 若没有配置则为null String host = protocolConfig.getHost(); //2. 再从ProviderConfig中取host. 若没有配置则为null if (provider != null && (host == null || host.length() == 0)) { host = provider.getHost(); } boolean anyhost = false; //3. 若取出的是本地host, 则继续取host if (NetUtils.isInvalidLocalHost(host)) { anyhost = true; try { //4. 通过InetAddress的方式获取Host //默认读取本机hosts中hostname对应的IP //如: 你在hosts中配置了 leo 172.16.11.111 //则读取的IP就是172.16.11.111 host = InetAddress.getLocalHost().getHostAddress(); } catch (UnknownHostException e) { logger.warn(e.getMessage(), e); } if (NetUtils.isInvalidLocalHost(host)) { if (registryURLs != null && registryURLs.size() > 0) { for (URL registryURL : registryURLs) { try { Socket socket = new Socket(); try { //5. 通过Socket的方式获取Host //一般解析到这里, 都会获取到正确的本地IP, 除非你有多网卡, 或者有VPN, 导致无法正常解析. SocketAddress addr = new InetSocketAddress(registryURL.getHost(), registryURL.getPort()); socket.connect(addr, 1000); host = socket.getLocalAddress().getHostAddress(); break; } finally { try { socket.close(); } catch (Throwable e) {} } } catch (Exception e) { logger.warn(e.getMessage(), e); } } } //6. 遍历本地网卡, 返回第一个合理的Host //最后一个大招. 当上述都解析不到时, 则会遍历本地网卡. //逐个获取IP, 直到有一个合理的IP为止. if (NetUtils.isInvalidLocalHost(host)) { host = NetUtils.getLocalHost(); } } } ... }