content: /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.activemq.broker.jmx;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class Log4JConfigView implements Log4JConfigViewMBean {
  
      private static final Logger LOG = LoggerFactory.getLogger(Log4JConfigView.class);
  
      @Override
      public String getRootLogLevel() throws Exception {
          ClassLoader cl = getClassLoader();
  
          if (!isLog4JAvailable(cl)) {
              return null;
          }
  
          Class<?> logManagerClass = getLogManagerClass(cl);
          Class<?> loggerClass = getLoggerClass(cl);
          if (logManagerClass == null || loggerClass == null) {
              return null;
          }
  
          Method getRootLogger = logManagerClass.getMethod("getRootLogger", new Class[]{});
          Method getLevel = loggerClass.getMethod("getLevel", new Class[]{});
          Object rootLogger = getRootLogger.invoke(null, (Object[])null);
  
          return getLevel.invoke(rootLogger, (Object[])null).toString();
      }
  
      @Override
      public void setRootLogLevel(String level) throws Exception {
          ClassLoader cl = getClassLoader();
  
          if (!isLog4JAvailable(cl)) {
              return;
          }
  
          Class<?> configuratorClass = getConfiguratorClass(cl);
          Class<?> loggerClass = getLoggerClass(cl);
          Class<?> levelClass = getLevelClass(cl);
          if (configuratorClass == null || levelClass == null || loggerClass == null) {
              return;
          }
  
          String targetLevel = level.toUpperCase(Locale.US);
          Method setRootLevel = configuratorClass.getMethod("setRootLevel", levelClass);
          Method toLevel = levelClass.getMethod("toLevel", String.class);
          Object newLevel = toLevel.invoke(null, targetLevel);
  
          // Check that the level conversion worked and that we got a level
          // that matches what was asked for.  A bad level name will result
          // in the lowest level value and we don't want to change unless we
          // matched what the user asked for.
          if (newLevel != null && newLevel.toString().equals(targetLevel)) {
              LOG.debug("Set level {} for root logger.", level);
              setRootLevel.invoke(configuratorClass, newLevel);
          }
      }
  
      @Override
      public List<String> getLoggers() throws Exception {
  
          ClassLoader cl = getClassLoader();
  
          if (!isLog4JAvailable(cl)) {
              return Collections.emptyList();
          }
  
          Class<?> logManagerClass = getLogManagerClass(cl);
          Class<?> loggerClass = getLoggerClass(cl);
          Class<?> loggerConfigClass = getLoggerConfigClass(cl);
          if (logManagerClass == null || loggerClass == null || loggerConfigClass == null) {
              return Collections.emptyList();
          }
  
          Method getContext = logManagerClass.getMethod("getContext", boolean.class);
          Object logContext = getContext.invoke(logManagerClass, false);
          Method getConfiguration = logContext.getClass().getMethod("getConfiguration");
          Object configuration = getConfiguration.invoke(logContext);
          Method getLoggers = configuration.getClass().getMethod("getLoggers");
  
          Method getName = loggerConfigClass.getMethod("getName");
  
          List<String> list = new ArrayList<String>();
          Map<String, ?> loggers = (Map<String, ?>)getLoggers.invoke(configuration);
  
          for (Object logger : loggers.values()) {
              if (logger != null) {
                  list.add((String) getName.invoke(logger, (Object[])null));
              }
          }
  
          LOG.debug("Found {} loggers", list.size());
  
          return list;
      }
  
      @Override
      public String getLogLevel(String loggerName) throws Exception {
  
          ClassLoader cl = getClassLoader();
  
          if (!isLog4JAvailable(cl)) {
              return null;
          }
  
          Class<?> logManagerClass = getLogManagerClass(cl);
          Class<?> loggerClass = getLoggerClass(cl);
          if (logManagerClass == null || loggerClass == null) {
              return null;
          }
  
          Method getLogger = logManagerClass.getMethod("getLogger", String.class);
          String logLevel = null;
  
          if (loggerName != null && !loggerName.isEmpty()) {
              Object logger = getLogger.invoke(null, loggerName);
              if (logger != null) {
                  LOG.debug("Found level {} for logger: {}", logLevel, loggerName);
                  Method getLevel = loggerClass.getMethod("getLevel", new Class[]{});
                  Object level = getLevel.invoke(logger, (Object[])null);
                  if (level != null) {
                      logLevel = level.toString();
                  } else {
                      Method getRootLogger = loggerClass.getMethod("getRootLogger", new Class[]{});
                      Object rootLogger = getRootLogger.invoke(null, (Object[])null);
                      logLevel = getLevel.invoke(rootLogger, (Object[])null).toString();
                  }
              }
          } else {
              throw new IllegalArgumentException("Logger names cannot be null or empty strings");
          }
  
          return logLevel;
      }
  
      @Override
      public void setLogLevel(String loggerName, String level) throws Exception {
  
          if (loggerName == null || loggerName.isEmpty()) {
              throw new IllegalArgumentException("Logger names cannot be null or empty strings");
          }
  
          if (level == null || level.isEmpty()) {
              throw new IllegalArgumentException("Level name cannot be null or empty strings");
          }
  
          ClassLoader cl = getClassLoader();
  
          if (!isLog4JAvailable(cl)) {
              return;
          }
  
          Class<?> configuratorClass = getConfiguratorClass(cl);
          Class<?> loggerClass = getLoggerClass(cl);
          Class<?> levelClass = getLevelClass(cl);
          if (configuratorClass == null || loggerClass == null || levelClass == null) {
              return;
          }
  
          String targetLevel = level.toUpperCase(Locale.US);
          Method setLevel = configuratorClass.getMethod("setLevel", String.class, levelClass);
          Method toLevel = levelClass.getMethod("toLevel", String.class);
  
          Object newLevel = toLevel.invoke(null, targetLevel);
  
          // Check that the level conversion worked and that we got a level
          // that matches what was asked for.  A bad level name will result
          // in the lowest level value and we don't want to change unless we
          // matched what the user asked for.
          if (newLevel != null && newLevel.toString().equals(targetLevel)) {
              LOG.debug("Set level {} for logger: {}", level, loggerName);
              setLevel.invoke(configuratorClass, loggerName, newLevel);
          }
      }
  
      @Override
      public void reloadLog4jProperties() throws Throwable {
          doReloadLog4jProperties();
      }
  
      //---------- Static Helper Methods ---------------------------------------//
  
      public static void doReloadLog4jProperties() throws Throwable {
          try {
              ClassLoader cl = Log4JConfigView.class.getClassLoader();
              Class<?> logManagerClass = getLogManagerClass(cl);
              if (logManagerClass == null) {
                  LOG.debug("Could not locate log4j classes on classpath.");
                  return;
              }
  
              Method getContext = logManagerClass.getMethod("getContext", boolean.class);
              Object logContext = getContext.invoke(logManagerClass, false);
              Method reconfigure = logContext.getClass().getMethod("reconfigure");
              reconfigure.invoke(logContext);
  			
          } catch (InvocationTargetException e) {
              throw e.getTargetException();
          }
      }
  
      public static boolean isLog4JAvailable() {
          return isLog4JAvailable(getClassLoader());
      }
  
      private static ClassLoader getClassLoader() {
          return Log4JConfigView.class.getClassLoader();
      }
  
      private static boolean isLog4JAvailable(ClassLoader cl) {
          if (getLogManagerClass(cl) != null) {
              return true;
          }
  
          LOG.debug("Could not locate log4j classes on classpath.");
  
          return false;
      }
  
      private static Class<?> getLogManagerClass(ClassLoader cl) {
          return getClass(cl, "org.apache.logging.log4j.LogManager");
      }
  
      private static Class<?> getLoggerClass(ClassLoader cl) {
          return getClass(cl, "org.apache.logging.log4j.Logger");
      }
  
      private static Class<?> getLoggerConfigClass(ClassLoader cl) {
          return getClass(cl, "org.apache.logging.log4j.core.config.LoggerConfig");
      }
  
      private static Class<?> getLevelClass(ClassLoader cl) {
          return getClass(cl, "org.apache.logging.log4j.Level");
      }
  
      private static Class<?> getConfiguratorClass(ClassLoader cl) {
          return getClass(cl, "org.apache.logging.log4j.core.config.Configurator");
      }
  
      private static Class<?> getClass(ClassLoader cl, String clazz) {
          Class<?> configuratorClass = null;
          try {
              configuratorClass = cl.loadClass(clazz);
          } catch (ClassNotFoundException e) {
          }
          return configuratorClass;
      }
  }
  