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.classic.model.processor;
015
016import ch.qos.logback.classic.joran.ReconfigureOnChangeTask;
017import ch.qos.logback.classic.model.ConfigurationModel;
018import ch.qos.logback.core.Context;
019import ch.qos.logback.core.joran.spi.ConfigurationWatchList;
020import ch.qos.logback.core.joran.util.ConfigurationWatchListUtil;
021import ch.qos.logback.core.model.Model;
022import ch.qos.logback.core.model.processor.ModelHandlerBase;
023import ch.qos.logback.core.model.processor.ModelHandlerException;
024import ch.qos.logback.core.model.processor.ModelInterpretationContext;
025import ch.qos.logback.core.spi.ConfigurationEvent;
026import ch.qos.logback.core.util.Duration;
027import ch.qos.logback.core.util.OptionHelper;
028
029import java.util.concurrent.ScheduledExecutorService;
030import java.util.concurrent.ScheduledFuture;
031import java.util.concurrent.TimeUnit;
032
033/**
034 * This is a subclass of {@link ConfigurationModelHandler} offering configuration reloading support.
035 *
036 */
037public class ConfigurationModelHandlerFull extends ConfigurationModelHandler {
038
039    public static String FAILED_WATCH_PREDICATE_MESSAGE_1 = "Missing watchable .xml or .properties files.";
040    public static String FAILED_WATCH_PREDICATE_MESSAGE_2 = "Watching .xml files requires that the main configuration file is reachable as a URL";
041
042    public ConfigurationModelHandlerFull(Context context) {
043        super(context);
044    }
045
046    static public ModelHandlerBase makeInstance2(Context context, ModelInterpretationContext mic) {
047        return new ConfigurationModelHandlerFull(context);
048    }
049
050    @Override
051    protected void processScanAttrib(ModelInterpretationContext mic, ConfigurationModel configurationModel) {
052        // override parent to do nothing
053    }
054
055    @Override
056    public void postHandle(ModelInterpretationContext mic, Model model) throws ModelHandlerException {
057        ConfigurationModel configurationModel = (ConfigurationModel) model;
058        // post handling of scan attribute works even we need to watch for included files because the main url is
059        // set in GenericXMLConfigurator very early in the configuration process
060        postProcessScanAttrib(mic, configurationModel);
061
062        ConfigurationWatchList cwl = ConfigurationWatchListUtil.getConfigurationWatchList(getContext());
063        if (cwl != null) {
064            try {
065                addInfo("Main configuration file URL: " + cwl.getMainURL());
066                addInfo("FileWatchList= {" + cwl.getFileWatchListAsStr()+"}");
067                addInfo("URLWatchList= {" + cwl.getUrlWatchListAsStr()+"}");
068            } catch(NoSuchMethodError e) {
069                addWarn("It looks like the version of logback-classic is more recent than");
070                addWarn("the version of logback-core. Please align the two versions.");
071            }
072        }
073    }
074
075    protected void postProcessScanAttrib(ModelInterpretationContext mic, ConfigurationModel configurationModel) {
076        String scanStr = mic.subst(configurationModel.getScanStr());
077        String scanPeriodStr = mic.subst(configurationModel.getScanPeriodStr());
078        detachedPostProcess(scanStr, scanPeriodStr);
079    }
080
081    /**
082     * This method is called from this class but also from logback-tyler.
083     *
084     * This method assumes that the variables scanStr and scanPeriodStr have undergone variable substitution
085     * as applicable to their current environment
086     *
087     * @param scanStr
088     * @param scanPeriodStr
089     * @since 1.5.0
090     */
091    public void detachedPostProcess(String scanStr, String scanPeriodStr) {
092        if (!OptionHelper.isNullOrEmptyOrAllSpaces(scanStr) && !"false".equalsIgnoreCase(scanStr)) {
093            ScheduledExecutorService scheduledExecutorService = context.getScheduledExecutorService();
094            boolean watchPredicateFulfilled = ConfigurationWatchListUtil.watchPredicateFulfilled(context);
095            if (!watchPredicateFulfilled) {
096                addWarn(FAILED_WATCH_PREDICATE_MESSAGE_1);
097                addWarn(FAILED_WATCH_PREDICATE_MESSAGE_2);
098                return;
099            }
100            ReconfigureOnChangeTask rocTask = new ReconfigureOnChangeTask();
101            rocTask.setContext(context);
102
103            addInfo("Registering a new ReconfigureOnChangeTask " + rocTask);
104
105            context.fireConfigurationEvent(ConfigurationEvent.newConfigurationChangeDetectorRegisteredEvent(rocTask));
106
107            Duration duration = getDurationOfScanPeriodAttribute(scanPeriodStr, SCAN_PERIOD_DEFAULT);
108
109            addInfo("Will scan for changes in [" + ConfigurationWatchListUtil.getConfigurationWatchList(context) + "] ");
110            // Given that included files are encountered at a later phase, the complete list
111            // of files to scan can only be determined when the configuration is loaded in full.
112            // However, scan can be active if mainURL is set. Otherwise, when changes are
113            // detected the top level config file cannot be accessed.
114            addInfo("Setting ReconfigureOnChangeTask scanning period to " + duration);
115
116            ScheduledFuture<?> scheduledFuture = scheduledExecutorService.scheduleAtFixedRate(rocTask, duration.getMilliseconds(), duration.getMilliseconds(),
117                            TimeUnit.MILLISECONDS);
118            rocTask.setScheduledFuture(scheduledFuture);
119            context.addScheduledFuture(scheduledFuture);
120        }
121
122    }
123
124    private Duration getDurationOfScanPeriodAttribute(String scanPeriodAttrib, Duration defaultDuration) {
125        Duration duration = null;
126
127        if (!OptionHelper.isNullOrEmptyOrAllSpaces(scanPeriodAttrib)) {
128            try {
129                duration = Duration.valueOf(scanPeriodAttrib);
130            } catch (IllegalStateException | IllegalArgumentException e) {
131                addWarn("Failed to parse 'scanPeriod' attribute [" + scanPeriodAttrib + "]", e);
132                // default duration will be set below
133            }
134        }
135
136        if (duration == null) {
137            addInfo("No 'scanPeriod' specified. Defaulting to " + defaultDuration.toString());
138            duration = defaultDuration;
139        }
140        return duration;
141    }
142}