001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.util;
015
016import ch.qos.logback.core.Context;
017import ch.qos.logback.core.CoreConstants;
018import ch.qos.logback.core.spi.ContextAware;
019import ch.qos.logback.core.spi.LifeCycle;
020import ch.qos.logback.core.status.OnConsoleStatusListener;
021import ch.qos.logback.core.status.OnErrorConsoleStatusListener;
022import ch.qos.logback.core.status.StatusListener;
023
024import static ch.qos.logback.core.CoreConstants.STDOUT;
025import static ch.qos.logback.core.CoreConstants.SYSOUT;
026
027public class StatusListenerConfigHelper {
028
029    public static void installIfAsked(Context context) {
030        String slClass = OptionHelper.getSystemProperty(CoreConstants.STATUS_LISTENER_CLASS_KEY);
031        if (!OptionHelper.isNullOrEmptyOrAllSpaces(slClass)) {
032            addStatusListener(context, slClass);
033        }
034    }
035
036    private static void addStatusListener(Context context, String listenerClassName) {
037        StatusListener listener = null;
038        if (SYSOUT.equalsIgnoreCase(listenerClassName) || STDOUT.equalsIgnoreCase(listenerClassName)) {
039            listener = new OnConsoleStatusListener();
040        } else {
041            listener = createListenerPerClassName(context, listenerClassName);
042        }
043        initAndAddListener(context, listener);
044    }
045
046    private static void initAndAddListener(Context context, StatusListener listener) {
047        if (listener != null) {
048            if (listener instanceof ContextAware) // LOGBACK-767
049                ((ContextAware) listener).setContext(context);
050
051            boolean effectivelyAdded = context.getStatusManager().add(listener);
052            if (effectivelyAdded && (listener instanceof LifeCycle)) {
053                ((LifeCycle) listener).start(); // LOGBACK-767
054            }
055        }
056    }
057
058    private static StatusListener createListenerPerClassName(Context context, String listenerClass) {
059        try {
060            return (StatusListener) OptionHelper.instantiateByClassName(listenerClass, StatusListener.class, context);
061        } catch (Exception e) {
062            // printing on the console is the best we can do
063            e.printStackTrace();
064            return null;
065        }
066    }
067
068    /**
069     * This utility method adds a new OnConsoleStatusListener to the context passed
070     * as parameter.
071     *
072     * @param context
073     * @since 1.0.1
074     */
075    static public void addOnConsoleListenerInstance(Context context, OnConsoleStatusListener onConsoleStatusListener) {
076        onConsoleStatusListener.setContext(context);
077        boolean effectivelyAdded = context.getStatusManager().add(onConsoleStatusListener);
078        if (effectivelyAdded) {
079            onConsoleStatusListener.start();
080        }
081    }
082}