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