现象：在进行数据测试时，无意发现某台机器返回的IP不正确，其返回的为127.0.0.1。但其它机器均为正常。
该IP是通过InetAddress.getLocalHost()获取IP地址，查看该方法见其注释为：
* If there is a security manager, its
* {@code checkConnect} method is called
* with the local host name and {@code -1}
* as its arguments to see if the operation is allowed.
* If the operation is not allowed, an InetAddress representing
* the loopback address is returned.
通过跟踪源码发现，是因为没有设置主机的hostname导致的。其解析的逻辑是根据
localHostName来获取的，而localHostName在虚拟机里面默认为localhost.localdomain，而localhost.localdomain对应的则默认为127.0.0.1，更改机器的hostname即可，其更改hostname方法如下：
hostnamectl set-hostname xxx
【Java获取机器IP】可以通过以下获取所有的IP（针对多网卡），并且对IP6地址过滤:
public static List getHostAddresses(Boolean filterIp6) {
List result = new ArrayList<>();
try {
Enumeration interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface networkInterface = interfaces.nextElement();
if (networkInterface.isLoopback() || networkInterface.isVirtual() || !networkInterface.isUp()) {
continue;
}
Enumeration address = networkInterface.getInetAddresses();
while (address.hasMoreElements()) {
InetAddress add = address.nextElement();
if (filterIp6 == null || filterIp6.booleanValue() == true) {
if (add.getHostAddress().contains(":")) {
continue;
}
}
result.add(add.getHostAddress());
}
}
} catch (SocketException e) {
e.printStackTrace();
}
return result;
}
