Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.util;

import static ch.qos.logback.core.CoreConstants.FA_FILENAME_COLLISION_MAP;
import static ch.qos.logback.core.CoreConstants.RFA_FILENAME_PATTERN_COLLISION_MAP;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import ch.qos.logback.core.Context;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.rolling.helper.FileNamePattern;
import ch.qos.logback.core.spi.ContextAwareBase;

public class ContextUtil extends ContextAwareBase {

    public ContextUtil(Context context) {
        setContext(context);
    }

    public static String getLocalHostName() throws UnknownHostException, SocketException {
        try {
            InetAddress localhost = InetAddress.getLocalHost();
            return localhost.getHostName();
        } 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
/**
     * Add the local host's name as a property
     */
    public String safelyGetLocalHostName() {
        try {
            String localhostName = getLocalHostName();
            return localhostName;
        } catch (UnknownHostException e) {
            addError("Failed to get local hostname", e);
        } catch (SocketException e) {
            addError("Failed to get local hostname", e);
        } catch (SecurityException e) {
            addError("Failed to get local hostname", e);
        }
        return CoreConstants.UNKNOWN_LOCALHOST;
    }

    public void addProperties(Properties props) {
        if (props == null) {
            return;
        }
        @SuppressWarnings("rawtypes")
        Iterator i = props.keySet().iterator();
        while (i.hasNext()) {
            String key = (String) i.next();
            context.putProperty(key, props.getProperty(key));
        }
    }

    public static Map<String, String> getFilenameCollisionMap(Context context) {
        if (context == null)
            return null;
        @SuppressWarnings("unchecked")
        Map<String, String> map = (Map<String, String>) context.getObject(FA_FILENAME_COLLISION_MAP);
        return map;
    }

    public static Map<String, FileNamePattern> getFilenamePatternCollisionMap(Context context) {
        if (context == null)
            return null;
        @SuppressWarnings("unchecked")
        Map<String, FileNamePattern> map = (Map<String, FileNamePattern>) context.getObject(RFA_FILENAME_PATTERN_COLLISION_MAP);
        return map;
    }
    
    public void addGroovyPackages(List<String> frameworkPackages) {
        // addFrameworkPackage(frameworkPackages, "groovy.lang");
        addFrameworkPackage(frameworkPackages, "org.codehaus.groovy.runtime");
    }

    public void addFrameworkPackage(List<String> frameworkPackages, String packageName) {
        if (!frameworkPackages.contains(packageName)) {
            frameworkPackages.add(packageName);
        }
    }

}