package ch.qos.logback.core.util;
   
   import java.net.InetAddress;
   import java.net.NetworkInterface;
   import java.net.SocketException;
   import java.net.UnknownHostException;
   import java.util.Enumeration;
   
   import ch.qos.logback.core.Context;
  import ch.qos.logback.core.CoreConstants;
  import ch.qos.logback.core.spi.ContextAwareBase;
  
  public class NetworkAddressUtil extends ContextAwareBase {
  
      public NetworkAddressUtil(Context context) {
          setContext(context);
      }
  
      public static String getLocalHostName() throws UnknownHostException, SocketException {
          try {
              InetAddress localhost = InetAddress.getLocalHost();
              return localhost.getHostName();
          } catch (UnknownHostException e) {
              return getLocalAddressAsString();
          }
      }
  
      public static String getCanonicalLocalHostName() throws UnknownHostException, SocketException {
          try {
              InetAddress localhost = InetAddress.getLocalHost();
              return localhost.getCanonicalHostName();
          } catch (UnknownHostException e) {
              return getLocalAddressAsString();
          }
      }
  
      private static String getLocalAddressAsString() throws UnknownHostException, SocketException {
          Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
          while (interfaces != null && interfaces.hasMoreElements()) {
              Enumeration<InetAddress> addresses = interfaces.nextElement().getInetAddresses();
              while (addresses != null && addresses.hasMoreElements()) {
                  InetAddress address = addresses.nextElement();
                  if (acceptableAddress(address)) {
                      return address.getHostAddress();
                  }
              }
          }
          throw new UnknownHostException();
      }
  
      private static boolean acceptableAddress(InetAddress address) {
          return address != null && !address.isLoopbackAddress() && !address.isAnyLocalAddress()
                  && !address.isLinkLocalAddress();
      }
  
      /**
       * Add the local host's name as a property
       */
      public String safelyGetLocalHostName() {
          try {
              String localhostName = getLocalHostName();
              return localhostName;
          } catch (UnknownHostException | SocketException | SecurityException e) {
              addError("Failed to get local hostname", e);
          }
          return CoreConstants.UNKNOWN_LOCALHOST;
      }
  
      public String safelyGetCanonicalLocalHostName() {
          try {
              String localhostName = getCanonicalLocalHostName();
              return localhostName;
          } catch (UnknownHostException | SocketException | SecurityException e) {
              addError("Failed to get canonical local hostname", e);
          }
          return CoreConstants.UNKNOWN_LOCALHOST;
  
      }
  
  }