Java類庫判斷兩臺機器之間網絡是否可達

import java.net.InetAddress;

public class Test {

    public static void main(String[] args) {
        String IP = "10.1.11.225";
        if (Test.ping(IP))
            System.out.println("SUCCESS - ping " + IP + " with no interface specified");
        else
            System.out.println("FAILURE - ping " + IP + " with no interface specified");

    }

    /**
     * 
     * @param host 主機地址
     * 
     * @return boolean
     * */
    public static boolean ping(String host) {
        String $host = host;
        try {
            InetAddress address = null;
            if ($host != null && $host.trim().length() > 0) {
                address = InetAddress.getByName($host);
            }
            if (address != null) {

            } else {
                System.out.println($host + " is unrecongized");
            }
            if (address.isReachable(5000))
                return true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
}