查询服务器的ip及java获取环形IP的方法与静态类修改成懒加载解决shortUrl服务启动正常但是调用接口异常报错

1.查询服务器ip
ip addr
# 或简写
ip a

hostname -i

 

import java.net.InetAddress;
ip = InetAddress.getLocalHost().getHostAddress();


2.非回环内网IPv4 ip 修改代码：
Enumeration<NetworkInterface> nets = NetworkInterface.getNetworkInterfaces();
            while (nets != null && nets.hasMoreElements()) {
                NetworkInterface nif = nets.nextElement();
                if (nif.isLoopback() || !nif.isUp()) {
                    continue;
                }
                Enumeration<InetAddress> addrs = nif.getInetAddresses();
                while (addrs.hasMoreElements()) {
                    InetAddress addr = addrs.nextElement();
                    if (addr instanceof Inet4Address && !addr.isLoopbackAddress()) {
                        return addr.getHostAddress();
                    }
                }
            }

            


private static final Map<Integer, String[]> MAP =
            new ImmutableMap.Builder<Integer, String[]>()          
            .put(0, ApplicationContextUtil.getFirstCode())
            .put(1, SECOND)
            .put(2, THIRD)
            .put(3, FOURTH)
            .put(4, FIFTH)
            .put(5, SIXTH)
            .build();


3.静态类修改成懒加载：

private static volatile Map<Integer, String[]> MAP;

    private static Map<Integer, String[]> getMap() {
        if (MAP == null) {
            synchronized (CodeUtil.class) {
                if (MAP == null) {
                    MAP = new ImmutableMap.Builder<Integer, String[]>()
                            .put(0, ApplicationContextUtil.getFirstCode())
                            .put(1, SECOND)
                            .put(2, THIRD)
                            .put(3, FOURTH)
                            .put(4, FIFTH)
                            .put(5, SIXTH)
                            .build();
                }
            }
        }
        return MAP;
    }