1   /*
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v2.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.classic.util;
15  
16  import ch.qos.logback.classic.ClassicConstants;
17  import ch.qos.logback.classic.LoggerContext;
18  import ch.qos.logback.classic.spi.Configurator;
19  import ch.qos.logback.classic.spi.ConfiguratorRank;
20  import ch.qos.logback.core.LogbackException;
21  import ch.qos.logback.core.joran.spi.JoranException;
22  import ch.qos.logback.core.spi.ContextAware;
23  import ch.qos.logback.core.spi.ContextAwareImpl;
24  import ch.qos.logback.core.util.CoreVersionUtil;
25  import ch.qos.logback.core.util.Loader;
26  import ch.qos.logback.core.util.StatusListenerConfigHelper;
27  import ch.qos.logback.core.util.VersionUtil;
28  
29  import java.util.Comparator;
30  import java.util.List;
31  
32  // contributors
33  // Ted Graham, Matt Fowles, see also http://jira.qos.ch/browse/LBCORE-32
34  
35  /**
36   * This class contains logback's logic for automatic configuration
37   *
38   * @author Ceki Gulcu
39   */
40  public class ContextInitializer {
41  
42      /**
43       *  @deprecated Please use ClassicConstants.AUTOCONFIG_FILE instead
44       */
45      final public static String AUTOCONFIG_FILE = ClassicConstants.AUTOCONFIG_FILE;
46      /**
47       * @deprecated Please use ClassicConstants.TEST_AUTOCONFIG_FILE instead
48       */
49      final public static String TEST_AUTOCONFIG_FILE = ClassicConstants.TEST_AUTOCONFIG_FILE;
50      /**
51       * @deprecated Please use ClassicConstants.CONFIG_FILE_PROPERTY instead
52       */
53      final public static String CONFIG_FILE_PROPERTY = ClassicConstants.CONFIG_FILE_PROPERTY;
54  
55      String[] INTERNAL_CONFIGURATOR_CLASSNAME_LIST = {"ch.qos.logback.classic.util.DefaultJoranConfigurator", "ch.qos.logback.classic.BasicConfigurator"};
56  
57      final LoggerContext loggerContext;
58  
59      final ContextAware contextAware;
60  
61      public ContextInitializer(LoggerContext loggerContext) {
62          this.loggerContext = loggerContext;
63          this.contextAware = new ContextAwareImpl(loggerContext, this);
64      }
65  
66      public void autoConfig() throws JoranException {
67          autoConfig(Configurator.class.getClassLoader());
68      }
69  
70  
71      public void autoConfig(ClassLoader classLoader) throws JoranException {
72  
73          // see https://github.com/qos-ch/logback/issues/715
74          classLoader = Loader.systemClassloaderIfNull(classLoader);
75  
76          checkVersions();
77  
78          StatusListenerConfigHelper.installIfAsked(loggerContext);
79  
80  
81          // invoke custom configurators
82          List<Configurator> configuratorList = ClassicEnvUtil.loadFromServiceLoader(Configurator.class, classLoader);
83          configuratorList.sort(rankComparator);
84          if (configuratorList.isEmpty()) {
85              contextAware.addInfo("No custom configurators were discovered as a service.");
86          } else {
87              printConfiguratorOrder(configuratorList);
88          }
89  
90          for (Configurator c : configuratorList) {
91              if (invokeConfigure(c) == Configurator.ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY)
92                  return;
93          }
94  
95          // invoke internal configurators
96          for (String configuratorClassName : INTERNAL_CONFIGURATOR_CLASSNAME_LIST) {
97              contextAware.addInfo("Trying to configure with "+configuratorClassName);
98              Configurator c = instantiateConfiguratorByClassName(configuratorClassName, classLoader);
99              if(c == null)
100                 continue;
101             if (invokeConfigure(c) == Configurator.ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY)
102                 return;
103         }
104     }
105 
106     private void checkVersions() {
107         try {
108             String coreVersion = CoreVersionUtil.getCoreVersionBySelfDeclaredProperties();
109             String classicVersion = ClassicVersionUtil.getVersionBySelfDeclaredProperties();
110             VersionUtil.checkForVersionEquality(loggerContext, coreVersion, classicVersion, "logback-core", "logback-classic");
111         }  catch(NoClassDefFoundError e) {
112             contextAware.addWarn("Missing ch.logback.core.util.VersionUtil class on classpath. The version of logback-core is probably older than 1.5.26.");
113         } catch (NoSuchMethodError e) {
114             contextAware.addWarn(e.toString());
115             contextAware.addWarn("The version of logback-core is probably older than 1.5.26.");
116         }
117     }
118 
119     private Configurator instantiateConfiguratorByClassName(String configuratorClassName, ClassLoader classLoader) {
120         try {
121             Class<?> classObj = classLoader.loadClass(configuratorClassName);
122             return (Configurator) classObj.getConstructor().newInstance();
123         } catch (ReflectiveOperationException  e) {
124             contextAware.addInfo("Instantiation failure: " + e.toString());
125             return null;
126         }
127     }
128 
129     /**
130      *
131      * @param configurator
132      * @return ExecutionStatus
133      */
134     private Configurator.ExecutionStatus invokeConfigure(Configurator configurator) {
135         try {
136             long start = System.currentTimeMillis();
137             contextAware.addInfo("Constructed configurator of type " + configurator.getClass());
138             configurator.setContext(loggerContext);
139             Configurator.ExecutionStatus status = configurator.configure(loggerContext);
140             printDuration(start, configurator, status);
141             return status;
142 
143         } catch (Exception e) {
144             throw new LogbackException(String.format("Failed to initialize or to run Configurator: %s",
145                     configurator != null ? configurator.getClass().getCanonicalName() : "null"), e);
146         }
147     }
148 
149     private void printConfiguratorOrder(List<Configurator> configuratorList) {
150         contextAware.addInfo("Here is a list of configurators discovered as a service, by rank: ");
151         for(Configurator c: configuratorList) {
152             contextAware.addInfo("  "+c.getClass().getName());
153         }
154         contextAware.addInfo("They will be invoked in order until ExecutionStatus.DO_NOT_INVOKE_NEXT_IF_ANY is returned.");
155     }
156 
157     private void printDuration(long start, Configurator configurator, Configurator.ExecutionStatus executionStatus) {
158         long end = System.currentTimeMillis();
159         long diff = end - start;
160         contextAware.addInfo( configurator.getClass().getName()+".configure() call lasted "+diff + " milliseconds. ExecutionStatus="+executionStatus);
161     }
162 
163     private Configurator.ExecutionStatus attemptConfigurationUsingJoranUsingReflexion(ClassLoader classLoader) {
164 
165         try {
166             Class<?> djcClass = classLoader.loadClass("ch.qos.logback.classic.util.DefaultJoranConfigurator");
167             Configurator c = (Configurator) djcClass.newInstance();
168             c.setContext(loggerContext);
169             return c.configure(loggerContext);
170         } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
171             contextAware.addError("unexpected exception while instantiating DefaultJoranConfigurator", e);
172             return Configurator.ExecutionStatus.INVOKE_NEXT_IF_ANY;
173         }
174 
175     }
176 
177     Comparator<Configurator> rankComparator = new Comparator<Configurator>() {
178         @Override
179         public int compare(Configurator c1, Configurator c2) {
180 
181             ConfiguratorRank r1 = c1.getClass().getAnnotation(ConfiguratorRank.class);
182             ConfiguratorRank r2 = c2.getClass().getAnnotation(ConfiguratorRank.class);
183 
184             int value1 = r1 == null ? ConfiguratorRank.DEFAULT : r1.value();
185             int value2 = r2 == null ? ConfiguratorRank.DEFAULT : r2.value();
186 
187             int result = compareRankValue(value1, value2);
188             // reverse the result for high to low sort
189             return (-result);
190         }
191     };
192 
193     private int compareRankValue(int value1, int value2) {
194         if(value1 > value2)
195             return 1;
196         else if (value1 == value2)
197             return 0;
198         else return -1;
199 
200     }
201 }