我正在尝试开发一个系统,其中有不同的节点运行在不同的系统或在同一系统的不同端口上。

现在,所有节点都创建了一个套接字,将目标IP作为称为引导节点的特殊节点的IP。然后,节点创建自己的ServerSocket并开始侦听连接。

引导节点维护一个节点列表,并在查询时返回它们。

现在我需要的是节点必须将其IP注册到引导节点。我尝试使用cli.getInetAddress()一旦客户端连接到引导节点的ServerSocket,但这不起作用。

我需要客户端注册其PPP IP,如果可用; 否则,局域网IP(如果可用); 否则,它必须注册127.0.0.1,假设它是同一台计算机。

使用代码:

System.out.println(Inet4Address.getLocalHost().getHostAddress());

or

System.out.println(InetAddress.getLocalHost().getHostAddress());

我的PPP连接IP地址是:117.204.44.192,但上面返回我192.168.1.2

EDIT

我正在使用以下代码:

Enumeration e = NetworkInterface.getNetworkInterfaces();
while(e.hasMoreElements())
{
    NetworkInterface n = (NetworkInterface) e.nextElement();
    Enumeration ee = n.getInetAddresses();
    while (ee.hasMoreElements())
    {
        InetAddress i = (InetAddress) ee.nextElement();
        System.out.println(i.getHostAddress());
    }
}

我能够获得所有网络接口相关的所有IP地址,但我如何区分它们?这是我得到的输出:

127.0.0.1
192.168.1.2
192.168.56.1
117.204.44.19

当前回答

在寻找“本地”地址时,应该注意到每台机器不仅只有一个网络接口,而且每个接口可以有自己的本地地址。这意味着您的机器总是拥有几个“本地”地址。

当您连接到不同的端点时,将自动选择使用不同的“本地”地址。例如,当你连接到google.com时,你是在使用一个“外部”本地地址;但是当您连接到本地主机时,您的本地地址总是localhost本身,因为localhost只是一个环回。

下面是当你与google.com通信时如何找到你的本地地址:

Socket socket = new Socket();
socket.connect(new InetSocketAddress("google.com", 80));
System.out.println(socket.getLocalAddress());
socket.close();

其他回答

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

一个Kotlin的例子,至少在Windows上可以工作,即使我的VPN是打开的。 (当VPN打开时,其他方法似乎失败了) 它只需要查找一次计算机的IP地址。从那时起,始终可以从存储的适配器信息中找到IP地址。

import java.net.NetworkInterface
import java.util.prefs.Preferences

class WindowsIP {
    companion object {
        val prefs = Preferences.userNodeForPackage(this::class.java)  //Get the current IP address for the wifi adapter whose information
        // has been stored by calling findWifiAdapter(currentIp) with the known current IP (from wifi properties or whatever)
        fun getIpAddress(): String {
            val wlanName = prefs.get("WlanName", "")
            val wlanDisplName = prefs.get("WlanDisplName", "")
            val addrCnt = prefs.getInt("wlanAddrCount", 0)
            val nis = NetworkInterface.getNetworkInterfaces()
            for (ni in nis) {
                if (ni.name == wlanName && ni.displayName == wlanDisplName) {
                    var count = 0
                    for (addr in ni.inetAddresses) {
                        if (count++ == addrCnt) {
                            return addr.hostAddress
                        }
                    }
                }
            }
            return "Unknown. Call findWifiAdapter() with current IP address"
        }

        fun findWifiAdapter(currentIP: String) {  //Find the wifi adapter using the current IP address and store the information
                val nis = NetworkInterface.getNetworkInterfaces()
                for(ni in nis) {
                    var count = 0;
                    for(adr in ni.inetAddresses) {
                        if(adr.hostAddress == currentIP) {
                            prefs.put("WlanName", ni.name)
                            prefs.put("WlanDisplName", ni.displayName)
                            prefs.putInt("wlanAddrCount", count)  //Probably always zero?
                        }
                        ++count
                    }
                }
        }
    }
}

通常当我试图找到我的公共IP地址,如cmyip.com或www.iplocation.net,我使用这种方式:

public static String myPublicIp() {

    /*nslookup myip.opendns.com resolver1.opendns.com*/
    String ipAdressDns  = "";
    try {
        String command = "nslookup myip.opendns.com resolver1.opendns.com";
        Process proc = Runtime.getRuntime().exec(command);

        BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));

        String s;
        while ((s = stdInput.readLine()) != null) {
            ipAdressDns  += s + "\n";
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    return ipAdressDns ;
}

你可以使用java.net.InetAddress API。 试试这个:

InetAddress.getLocalHost().getHostAddress();

编辑1:更新后的代码,因为之前的链接,不再存在

import java.io.*;
import java.net.*;

public class GetMyIP {
    public static void main(String[] args) {
        URL url = null;
        BufferedReader in = null;
        String ipAddress = "";
        try {
            url = new URL("http://bot.whatismyipaddress.com");
            in = new BufferedReader(new InputStreamReader(url.openStream()));
            ipAddress = in.readLine().trim();
            /* IF not connected to internet, then
             * the above code will return one empty
             * String, we can check it's length and
             * if length is not greater than zero, 
             * then we can go for LAN IP or Local IP
             * or PRIVATE IP
             */
            if (!(ipAddress.length() > 0)) {
                try {
                    InetAddress ip = InetAddress.getLocalHost();
                    System.out.println((ip.getHostAddress()).trim());
                    ipAddress = (ip.getHostAddress()).trim();
                } catch(Exception exp) {
                    ipAddress = "ERROR";
                }
            }
        } catch (Exception ex) {
            // This try will give the Private IP of the Host.
            try {
                InetAddress ip = InetAddress.getLocalHost();
                System.out.println((ip.getHostAddress()).trim());
                ipAddress = (ip.getHostAddress()).trim();
            } catch(Exception exp) {
                ipAddress = "ERROR";
            }
            //ex.printStackTrace();
        }
        System.out.println("IP Address: " + ipAddress);
    }
}

实际版本:这停止工作

希望这段代码可以帮助你实现这一点:

// Method to get the IP Address of the Host.
private String getIP()
{
    // This try will give the Public IP Address of the Host.
    try
    {
        URL url = new URL("http://automation.whatismyip.com/n09230945.asp");
        BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
        String ipAddress = new String();
        ipAddress = (in.readLine()).trim();
        /* IF not connected to internet, then
         * the above code will return one empty
         * String, we can check it's length and
         * if length is not greater than zero, 
         * then we can go for LAN IP or Local IP
         * or PRIVATE IP
         */
        if (!(ipAddress.length() > 0))
        {
            try
            {
                InetAddress ip = InetAddress.getLocalHost();
                System.out.println((ip.getHostAddress()).trim());
                return ((ip.getHostAddress()).trim());
            }
            catch(Exception ex)
            {
                return "ERROR";
            }
        }
        System.out.println("IP Address is : " + ipAddress);

        return (ipAddress);
    }
    catch(Exception e)
    {
        // This try will give the Private IP of the Host.
        try
        {
            InetAddress ip = InetAddress.getLocalHost();
            System.out.println((ip.getHostAddress()).trim());
            return ((ip.getHostAddress()).trim());
        }
        catch(Exception ex)
        {
            return "ERROR";
        }
    }
}