001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2022, 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.model.processor;
015
016import ch.qos.logback.core.Context;
017import ch.qos.logback.core.CoreConstants;
018import ch.qos.logback.core.hook.DefaultShutdownHook;
019import ch.qos.logback.core.hook.ShutdownHook;
020import ch.qos.logback.core.hook.ShutdownHookBase;
021import ch.qos.logback.core.model.Model;
022import ch.qos.logback.core.model.ShutdownHookModel;
023import ch.qos.logback.core.util.DynamicClassLoadingException;
024import ch.qos.logback.core.util.IncompatibleClassException;
025import ch.qos.logback.core.util.OptionHelper;
026
027public class ShutdownHookModelHandler extends ModelHandlerBase {
028
029    static final String OLD_SHUTDOWN_HOOK_CLASSNAME = "ch.qos.logback.core.hook.DelayingShutdownHook";
030    static final String DEFAULT_SHUTDOWN_HOOK_CLASSNAME = DefaultShutdownHook.class.getName();
031    static public final String RENAME_WARNING = OLD_SHUTDOWN_HOOK_CLASSNAME + " was renamed as "+ DEFAULT_SHUTDOWN_HOOK_CLASSNAME;
032
033    public ShutdownHookModelHandler(Context context) {
034        super(context);
035    }
036    boolean inError = false;
037    ShutdownHook  hook = null;
038
039    static public ModelHandlerBase makeInstance(Context context, ModelInterpretationContext mic) {
040        return new ShutdownHookModelHandler(context);
041    }
042
043    @Override
044    protected Class<ShutdownHookModel> getSupportedModelClass() {
045        return ShutdownHookModel.class;
046    }
047
048    @Override
049    public void handle(ModelInterpretationContext mic, Model model) {
050
051        ShutdownHookModel shutdownHookModel = (ShutdownHookModel) model;
052
053        String className = shutdownHookModel.getClassName();
054        if (OptionHelper.isNullOrEmptyOrAllSpaces(className)) {
055            className = DEFAULT_SHUTDOWN_HOOK_CLASSNAME;
056            addInfo("Assuming className [" + className + "]");
057        } else {
058            className = mic.getImport(className);
059            if(className.equals(OLD_SHUTDOWN_HOOK_CLASSNAME)) {
060                className = DEFAULT_SHUTDOWN_HOOK_CLASSNAME;
061                addWarn(RENAME_WARNING);
062                addWarn("Please use the new class name");
063            }
064        }
065
066        addInfo("About to instantiate shutdown hook of type [" + className + "]");
067
068        try {
069            hook = (ShutdownHookBase) OptionHelper.instantiateByClassName(className, ShutdownHookBase.class, context);
070            hook.setContext(context);
071        } catch (IncompatibleClassException | DynamicClassLoadingException e) {
072            addError("Could not create a shutdown hook of type [" + className + "].", e);
073            inError = true;
074            return;
075        }
076
077        mic.pushObject(hook);
078    }
079
080    @Override
081    public void postHandle(ModelInterpretationContext mic, Model model) throws ModelHandlerException {
082        if (inError) {
083            return;
084        }
085        Object o = mic.peekObject();
086
087        if (o != hook) {
088            addWarn("The object on the top the of the stack is not the hook object pushed earlier.");
089        } else {
090            Thread hookThread = new Thread(hook, "Logback shutdown hook [" + context.getName() + "]");
091            addInfo("Registering shutdown hook with JVM runtime.");
092            context.putObject(CoreConstants.SHUTDOWN_HOOK_THREAD, hookThread);
093            Runtime.getRuntime().addShutdownHook(hookThread);
094
095            mic.popObject();
096        }
097    }
098}