Java獲取本機ip地址,並掃描本機所在局域網的電腦設備

Java獲取本機IP地址,並根據IP地址的網段,掃描局域網里面的電腦設備;

import java.io.IOException;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;

/**
 * 類注解
 *
 * @author 塵世間迷茫的小書童
 * @date 2020年06月23日 17:31
 */
public class Demo {

    public static void main(String[] args) {
        Set<String> set = getIpAddress();
        if(set.size() > 0) {
            set.forEach(ip -> {
                System.out.println("本機ip: " + ip);
            });
        }
        set.remove("127.0.0.1");
        scannerNetwork(set);
        System.out.println("掃描完畢...");
        System.exit(0);
    }

    /**
     * 獲取本機的IP地址（包括ipv4和ipv6） <br>
     * 包含回環地址127.0.0.1和0:0:0:0:0:0:0:1
     */
    private static Set<String> getIpAddress() {
        Set<String> ipList = new HashSet<>();
        try {
            Enumeration<NetworkInterface> allNetInterfaces = NetworkInterface.getNetworkInterfaces();
            InetAddress ip = null;
            while (allNetInterfaces.hasMoreElements()) {
                NetworkInterface netInterface = (NetworkInterface) allNetInterfaces.nextElement();
                // 排除虛擬接口和沒有啟動運行的接口
                if (netInterface.isVirtual() || !netInterface.isUp()) {
                    continue;
                } else {
                    Enumeration<InetAddress> addresses = netInterface.getInetAddresses();
                    while (addresses.hasMoreElements()) {
                        ip = addresses.nextElement();
//                        if (ip != null && (ip instanceof Inet4Address || ip instanceof Inet6Address)) {
//                            ipList.add(ip.getHostAddress());
//                        }
                        if (ip != null && (ip instanceof Inet4Address)) {
                            ipList.add(ip.getHostAddress());
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ipList;
    }


    /**
     * 根據本機ip掃描局域網設備
     * @param set
     */
    private static void scannerNetwork(Set<String> set) {
        try {
            set.forEach(address -> {
                // 設置IP地址網段
                String ips = getNetworkSegment(address);

                System.out.println("開始掃描 " + ips + "網段...");

                String ip;
                InetAddress addip = null;
                // 遍歷IP地址
                for (int i = 1; i < 255; i++) {
                    ip = ips + i;
                    try {
                        addip = InetAddress.getByName(ip);
                    } catch (UnknownHostException e) {
                        System.out.println("找不到主機: " + ip);
                    }
                    // 獲取登錄過的設備
                    if (!ip.equals(addip.getHostName())) {
                        try {
                            // 檢查設備是否在線，其中1000ms指定的是超時時間
                            boolean status = InetAddress.getByName(addip.getHostName()).isReachable(1000); // 當返回值是true時，說明host是可用的，false則不可。
                            System.out.println("IP地址為:" + ip + "\t\t設備名稱為: " + addip.getHostName() + "\t\t是否可用: "
                                    + (status ? "可用" : "不可用"));
                        } catch (UnknownHostException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            });
        } catch (Exception uhe) {
            System.err.println("Unable to find: " + uhe.getLocalizedMessage());
        }
    }


    /**
     * 根據ip獲取網段
     * @param ip
     * @return
     */
    private static String getNetworkSegment(String ip) {
        int startIndex = ip.lastIndexOf(".");
        return ip.substring(0, startIndex+1);
    }

}