首先导入类

import java.net.InetAddress;

在课堂上

  InetAddress iAddress = InetAddress.getLocalHost();
  String currentIp = iAddress.getHostAddress();
  System.out.println("Current IP address : " +currentIp); //gives only host address

你可以使用java.net.InetAddress API。 试试这个:

InetAddress.getLocalHost().getHostAddress();

如果您的机器是网络的一部分，那么它将获取您的网络的IP地址

try {
    System.out.println(InetAddress.getLocalHost().getHostAddress());
} catch (UnknownHostException e) {
    e.printStackTrace();
}

在这里发布来自https://issues.apache.org/jira/browse/JCS-40的测试IP歧义变通代码(InetAddress.getLocalHost()在Linux系统上是歧义的):

/**
 * Returns an <code>InetAddress</code> object encapsulating what is most likely the machine's LAN IP address.
 * <p/>
 * This method is intended for use as a replacement of JDK method <code>InetAddress.getLocalHost</code>, because
 * that method is ambiguous on Linux systems. Linux systems enumerate the loopback network interface the same
 * way as regular LAN network interfaces, but the JDK <code>InetAddress.getLocalHost</code> method does not
 * specify the algorithm used to select the address returned under such circumstances, and will often return the
 * loopback address, which is not valid for network communication. Details
 * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4665037">here</a>.
 * <p/>
 * This method will scan all IP addresses on all network interfaces on the host machine to determine the IP address
 * most likely to be the machine's LAN address. If the machine has multiple IP addresses, this method will prefer
 * a site-local IP address (e.g. 192.168.x.x or 10.10.x.x, usually IPv4) if the machine has one (and will return the
 * first site-local address if the machine has more than one), but if the machine does not hold a site-local
 * address, this method will return simply the first non-loopback address found (IPv4 or IPv6).
 * <p/>
 * If this method cannot find a non-loopback address using this selection algorithm, it will fall back to
 * calling and returning the result of JDK method <code>InetAddress.getLocalHost</code>.
 * <p/>
 *
 * @throws UnknownHostException If the LAN address of the machine cannot be found.
 */
private static InetAddress getLocalHostLANAddress() throws UnknownHostException {
    try {
        InetAddress candidateAddress = null;
        // Iterate all NICs (network interface cards)...
        for (Enumeration ifaces = NetworkInterface.getNetworkInterfaces(); ifaces.hasMoreElements();) {
            NetworkInterface iface = (NetworkInterface) ifaces.nextElement();
            // Iterate all IP addresses assigned to each card...
            for (Enumeration inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements();) {
                InetAddress inetAddr = (InetAddress) inetAddrs.nextElement();
                if (!inetAddr.isLoopbackAddress()) {

                    if (inetAddr.isSiteLocalAddress()) {
                        // Found non-loopback site-local address. Return it immediately...
                        return inetAddr;
                    }
                    else if (candidateAddress == null) {
                        // Found non-loopback address, but not necessarily site-local.
                        // Store it as a candidate to be returned if site-local address is not subsequently found...
                        candidateAddress = inetAddr;
                        // Note that we don't repeatedly assign non-loopback non-site-local addresses as candidates,
                        // only the first. For subsequent iterations, candidate will be non-null.
                    }
                }
            }
        }
        if (candidateAddress != null) {
            // We did not find a site-local address, but we found some other non-loopback address.
            // Server might have a non-site-local address assigned to its NIC (or it might be running
            // IPv6 which deprecates the "site-local" concept).
            // Return this non-loopback candidate address...
            return candidateAddress;
        }
        // At this point, we did not find a non-loopback address.
        // Fall back to returning whatever InetAddress.getLocalHost() returns...
        InetAddress jdkSuppliedAddress = InetAddress.getLocalHost();
        if (jdkSuppliedAddress == null) {
            throw new UnknownHostException("The JDK InetAddress.getLocalHost() method unexpectedly returned null.");
        }
        return jdkSuppliedAddress;
    }
    catch (Exception e) {
        UnknownHostException unknownHostException = new UnknownHostException("Failed to determine LAN address: " + e);
        unknownHostException.initCause(e);
        throw unknownHostException;
    }
}

你可以使用java的InetAddress类来实现这个目的。

InetAddress IP=InetAddress.getLocalHost();
System.out.println("IP of my system is := "+IP.getHostAddress());

my system = IP的输出是:= 10.100.98.228

getHostAddress()返回

以文本形式返回IP地址字符串。

或者你也可以这样做

InetAddress IP=InetAddress.getLocalHost();
System.out.println(IP.toString());

我的系统Output = IP为:= RanRag-PC/10.100.98.228

你的计算机可以有多个网络接口，每个网络接口有多个inetaddress。如果过滤掉任何本地地址，则提醒的地址是非本地地址，其中可以有一个、没有或多个。

不幸的是，Java中的网络API仍然使用(旧的)枚举而不是迭代器和流，我们可以通过将它们包装为流来进行对抗。所以我们要做的就是

所有网络接口及其地址的流，以及 过滤掉本地的

代码:

private Stream<InetAddress> getNonLocalIpAddresses() throws IOException {
    return enumerationAsStream(NetworkInterface.getNetworkInterfaces())
        .flatMap(networkInterface -> enumerationAsStream(networkInterface.getInetAddresses()))
        .filter(inetAddress -> !inetAddress.isAnyLocalAddress())
        .filter(inetAddress -> !inetAddress.isSiteLocalAddress())
        .filter(inetAddress -> !inetAddress.isLoopbackAddress())
        .filter(inetAddress -> !inetAddress.isLinkLocalAddress());
}

在我的机器上，这目前返回两个IPv6地址。

要获得这些inetaddress中的第一个:

private String getMyIp() throws IOException {
    return getNonLocalIpAddresses()
        .map(InetAddress::getHostAddress)
        .findFirst()
        .orElseThrow(NoSuchElementException::new);
}

将枚举包装为流的方法:

public static <T> Stream<T> enumerationAsStream(Enumeration<T> e) {
    return StreamSupport.stream(
        Spliterators.spliteratorUnknownSize(
            new Iterator<>() {
                public T next() { return e.nextElement();  }
                public boolean hasNext() { return e.hasMoreElements(); }
            }, Spliterator.ORDERED), false);
}