使用Java获取本机IP出错 java.net.UnknownHostException

Question

使用这段代码获取IP 就会报错 

InetAddress.getLocalHost().getHostName();

错误堆栈信息：

00:50:56.166 [main] ERROR RocketmqCommon - Failed to obtain the host name
java.net.UnknownHostException: HEIHEI: HEIHEI
	at java.net.InetAddress.getLocalHost(InetAddress.java:1505) ~[na:1.8.0_131]
	at org.apache.rocketmq.common.BrokerConfig.localHostName(BrokerConfig.java:200) [classes/:na]
	at org.apache.rocketmq.common.BrokerConfig.<init>(BrokerConfig.java:40) [classes/:na]
	at org.apache.rocketmq.broker.BrokerStartup.createBrokerController(BrokerStartup.java:124) [classes/:na]
	at org.apache.rocketmq.broker.BrokerStartup.main(BrokerStartup.java:69) [classes/:na]
Caused by: java.net.UnknownHostException: HEIHEI
	at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method) ~[na:1.8.0_131]
	at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928) ~[na:1.8.0_131]
	at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323) ~[na:1.8.0_131]
	at java.net.InetAddress.getLocalHost(InetAddress.java:1500) ~[na:1.8.0_131]
	... 4 common frames omitted

Process finished with exit code -3

电脑： win 10  求大佬帮忙看看，跪谢。

Answer 1

不建议使用这种方式获取ip，你可以试试这个

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;

public class IP {
    public static void main(String[] args) throws UnknownHostException {
        
        System.out.println(getLocalHostExactAddress().getHostAddress());
    }

    public static InetAddress getLocalHostExactAddress() {
        try {
            InetAddress candidateAddress = null;

            Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
            while (networkInterfaces.hasMoreElements()) {
                NetworkInterface iface = networkInterfaces.nextElement();
                // 该网卡接口下的ip会有多个，也需要一个个的遍历，找到自己所需要的
                for (Enumeration<InetAddress> inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements(); ) {
                    InetAddress inetAddr = inetAddrs.nextElement();
                    // 排除loopback回环类型地址（不管是IPv4还是IPv6 只要是回环地址都会返回true）
                    if (!inetAddr.isLoopbackAddress()) {
                        if (inetAddr.isSiteLocalAddress()) {
                            // 如果是site-local地址，就是它了 就是我们要找的
                            // ~~~~~~~~~~~~~绝大部分情况下都会在此处返回你的ip地址值~~~~~~~~~~~~~
                            return inetAddr;
                        }

                        // 若不是site-local地址 那就记录下该地址当作候选
                        if (candidateAddress == null) {
                            candidateAddress = inetAddr;
                        }

                    }
                }
            }

            // 如果出去loopback回环地之外无其它地址了，那就回退到原始方案吧
            return candidateAddress == null ? InetAddress.getLocalHost() : candidateAddress;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }


}