ClassLoaderLogManager.java
/*
* 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.juli;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;
/**
* Per classloader LogManager implementation. For light debugging, set the system property
* <code>org.apache.juli.ClassLoaderLogManager.debug=true</code>. Short configuration information will be sent to
* <code>System.err</code>.
*/
public class ClassLoaderLogManager extends LogManager {
private static ThreadLocal<Boolean> addingLocalRootLogger = ThreadLocal.withInitial(() -> Boolean.FALSE);
public static final String DEBUG_PROPERTY = ClassLoaderLogManager.class.getName() + ".debug";
private final class Cleaner extends Thread {
@Override
public void run() {
if (useShutdownHook) {
shutdown();
}
}
}
// ------------------------------------------------------------Constructors
public ClassLoaderLogManager() {
super();
try {
Runtime.getRuntime().addShutdownHook(new Cleaner());
} catch (IllegalStateException ise) {
// We are probably already being shutdown. Ignore this error.
}
}
// -------------------------------------------------------------- Variables
/**
* Map containing the classloader information, keyed per classloader. A weak hashmap is used to ensure no
* classloader reference is leaked from application redeployment.
*/
protected final Map<ClassLoader, ClassLoaderLogInfo> classLoaderLoggers = new WeakHashMap<>(); // Guarded by this
/**
* This prefix is used to allow using prefixes for the properties names of handlers and their subcomponents.
*/
protected final ThreadLocal<String> prefix = new ThreadLocal<>();
/**
* Determines if the shutdown hook is used to perform any necessary clean-up such as flushing buffered handlers on
* JVM shutdown. Defaults to <code>true</code> but may be set to false if another component ensures that
* {@link #shutdown()} is called.
*/
protected volatile boolean useShutdownHook = true;
// ------------------------------------------------------------- Properties
public boolean isUseShutdownHook() {
return useShutdownHook;
}
public void setUseShutdownHook(boolean useShutdownHook) {
this.useShutdownHook = useShutdownHook;
}
// --------------------------------------------------------- Public Methods
/**
* Add the specified logger to the classloader local configuration.
*
* @param logger The logger to be added
*/
@Override
public synchronized boolean addLogger(final Logger logger) {
final String loggerName = logger.getName();
ClassLoader classLoader = getClassLoader();
ClassLoaderLogInfo info = getClassLoaderInfo(classLoader);
if (info.loggers.containsKey(loggerName)) {
return false;
}
info.loggers.put(loggerName, logger);
// Apply initial level for new logger
final String levelString = getProperty(loggerName + ".level");
if (levelString != null) {
logger.setLevel(Level.parse(levelString.trim()));
}
// Always instantiate parent loggers so that
// we can control log categories even during runtime
int dotIndex = loggerName.lastIndexOf('.');
if (dotIndex >= 0) {
final String parentName = loggerName.substring(0, dotIndex);
Logger.getLogger(parentName);
}
// Find associated node
LogNode node = info.rootNode.findNode(loggerName);
node.logger = logger;
// Set parent logger
Logger parentLogger = node.findParentLogger();
if (parentLogger != null) {
logger.setParent(parentLogger);
}
// Tell children we are their new parent
node.setParentLogger(logger);
// Add associated handlers, if any are defined using the .handlers property.
// In this case, handlers of the parent logger(s) will not be used
String handlers = getProperty(loggerName + ".handlers");
if (handlers != null) {
logger.setUseParentHandlers(false);
StringTokenizer tok = new StringTokenizer(handlers, ",");
while (tok.hasMoreTokens()) {
String handlerName = (tok.nextToken().trim());
Handler handler = null;
ClassLoader current = classLoader;
while (current != null) {
info = classLoaderLoggers.get(current);
if (info != null) {
handler = info.handlers.get(handlerName);
if (handler != null) {
break;
}
}
current = current.getParent();
}
if (handler != null) {
logger.addHandler(handler);
}
}
}
// Parse useParentHandlers to set if the logger should delegate to its parent.
// Unlike java.util.logging, the default is to not delegate if a list of handlers
// has been specified for the logger.
String useParentHandlersString = getProperty(loggerName + ".useParentHandlers");
if (Boolean.parseBoolean(useParentHandlersString)) {
logger.setUseParentHandlers(true);
}
return true;
}
/**
* Get the logger associated with the specified name inside the classloader local configuration. If this returns
* null, and the call originated for Logger.getLogger, a new logger with the specified name will be instantiated and
* added using addLogger.
*
* @param name The name of the logger to retrieve
*/
@Override
public synchronized Logger getLogger(final String name) {
ClassLoader classLoader = getClassLoader();
return getClassLoaderInfo(classLoader).loggers.get(name);
}
/**
* Get an enumeration of the logger names currently defined in the classloader local configuration.
*/
@Override
public synchronized Enumeration<String> getLoggerNames() {
ClassLoader classLoader = getClassLoader();
return Collections.enumeration(getClassLoaderInfo(classLoader).loggers.keySet());
}
/**
* Get the value of the specified property in the classloader local configuration.
*
* @param name The property name
*/
@Override
public String getProperty(String name) {
// Use a ThreadLocal to work around
// https://bugs.openjdk.java.net/browse/JDK-8195096
if (".handlers".equals(name) && !addingLocalRootLogger.get().booleanValue()) {
return null;
}
String prefix = this.prefix.get();
String result = null;
// If a prefix is defined look for a prefixed property first
if (prefix != null) {
result = findProperty(prefix + name);
}
// If there is no prefix or no property match with the prefix try just
// the name
if (result == null) {
result = findProperty(name);
}
// Simple property replacement (mostly for folder names)
if (result != null) {
result = replace(result);
}
return result;
}
private synchronized String findProperty(String name) {
ClassLoader classLoader = getClassLoader();
ClassLoaderLogInfo info = getClassLoaderInfo(classLoader);
String result = info.props.getProperty(name);
// If the property was not found, and the current classloader had no
// configuration (property list is empty), look for the parent classloader
// properties.
if ((result == null) && (info.props.isEmpty())) {
if (classLoader != null) {
ClassLoader current = classLoader.getParent();
while (current != null) {
info = classLoaderLoggers.get(current);
if (info != null) {
result = info.props.getProperty(name);
if ((result != null) || (!info.props.isEmpty())) {
break;
}
}
current = current.getParent();
}
}
if (result == null) {
result = super.getProperty(name);
}
}
return result;
}
@Override
public void readConfiguration() throws IOException, SecurityException {
readConfiguration(getClassLoader());
}
@Override
public void readConfiguration(InputStream is) throws IOException, SecurityException {
reset();
readConfiguration(is, getClassLoader());
}
@Override
public synchronized void reset() throws SecurityException {
Thread thread = Thread.currentThread();
if (thread.getClass().getName().startsWith("java.util.logging.LogManager$")) {
// Ignore the call from java.util.logging.LogManager.Cleaner,
// because we have our own shutdown hook
return;
}
ClassLoader classLoader = getClassLoader();
ClassLoaderLogInfo clLogInfo = getClassLoaderInfo(classLoader);
resetLoggers(clLogInfo);
// Do not call super.reset(). It should be a NO-OP as all loggers should
// have been registered via this manager. Very rarely a
// ConcurrentModificationException has been seen in the unit tests when
// calling super.reset() and that exception could cause the stop of a
// web application to fail.
}
/**
* Shuts down the logging system.
*/
public synchronized void shutdown() {
// The JVM is being shutdown. Make sure all loggers for all class
// loaders are shutdown
for (ClassLoaderLogInfo clLogInfo : classLoaderLoggers.values()) {
resetLoggers(clLogInfo);
}
}
// -------------------------------------------------------- Private Methods
private void resetLoggers(ClassLoaderLogInfo clLogInfo) {
// This differs from LogManager#resetLogger() in that we close not all
// handlers of all loggers, but only those that are present in our
// ClassLoaderLogInfo#handlers list. That is because our #addLogger(..)
// method can use handlers from the parent class loaders, and closing
// handlers that the current class loader does not own would be not
// good.
for (Logger logger : clLogInfo.loggers.values()) {
Handler[] handlers = logger.getHandlers();
for (Handler handler : handlers) {
logger.removeHandler(handler);
}
}
for (Handler handler : clLogInfo.handlers.values()) {
try {
handler.close();
} catch (Exception e) {
// Ignore
}
}
clLogInfo.handlers.clear();
}
// ------------------------------------------------------ Protected Methods
/**
* Retrieve the configuration associated with the specified classloader. If it does not exist, it will be created.
* If no class loader is specified, the class loader used to load this class is used.
*
* @param classLoader The class loader for which we will retrieve or build the configuration
*
* @return the log configuration
*/
protected synchronized ClassLoaderLogInfo getClassLoaderInfo(ClassLoader classLoader) {
if (classLoader == null) {
classLoader = this.getClass().getClassLoader();
}
ClassLoaderLogInfo info = classLoaderLoggers.get(classLoader);
if (info == null) {
try {
readConfiguration(classLoader);
} catch (IOException e) {
// Ignore
}
info = classLoaderLoggers.get(classLoader);
}
return info;
}
/**
* Read configuration for the specified classloader.
*
* @param classLoader The classloader
*
* @throws IOException Error reading configuration
*/
protected synchronized void readConfiguration(ClassLoader classLoader) throws IOException {
InputStream is = null;
// Special case for URL classloaders which are used in containers:
// only look in the local repositories to avoid redefining loggers 20 times
if (classLoader instanceof URLClassLoader) {
URL logConfig = ((URLClassLoader) classLoader).findResource("logging.properties");
if (null != logConfig) {
if (Boolean.getBoolean(DEBUG_PROPERTY)) {
System.err.println(getClass().getName() + ".readConfiguration(): " +
"Found logging.properties at " + logConfig);
}
is = classLoader.getResourceAsStream("logging.properties");
} else {
if (Boolean.getBoolean(DEBUG_PROPERTY)) {
System.err.println(getClass().getName() + ".readConfiguration(): " + "Found no logging.properties");
}
}
}
if ((is == null) && (classLoader == ClassLoader.getSystemClassLoader())) {
String configFileStr = System.getProperty("java.util.logging.config.file");
if (configFileStr != null) {
try {
is = new FileInputStream(replace(configFileStr));
} catch (IOException e) {
System.err.println("Configuration error");
e.printStackTrace();
}
}
// Try the default JVM configuration
if (is == null) {
File defaultFile = new File(new File(System.getProperty("java.home"), "conf"), "logging.properties");
try {
is = new FileInputStream(defaultFile);
} catch (IOException e) {
System.err.println("Configuration error");
e.printStackTrace();
}
}
}
Logger localRootLogger = new RootLogger();
if (is == null) {
// Retrieve the root logger of the parent classloader instead
ClassLoader current = classLoader.getParent();
ClassLoaderLogInfo info = null;
while (current != null && info == null) {
info = getClassLoaderInfo(current);
current = current.getParent();
}
if (info != null) {
localRootLogger.setParent(info.rootNode.logger);
}
}
ClassLoaderLogInfo info = new ClassLoaderLogInfo(new LogNode(null, localRootLogger));
classLoaderLoggers.put(classLoader, info);
if (is != null) {
readConfiguration(is, classLoader);
}
if (localRootLogger.getParent() == null && localRootLogger.getLevel() == null) {
localRootLogger.setLevel(Level.INFO);
}
try {
// Use a ThreadLocal to work around
// https://bugs.openjdk.java.net/browse/JDK-8195096
addingLocalRootLogger.set(Boolean.TRUE);
addLogger(localRootLogger);
} finally {
addingLocalRootLogger.set(Boolean.FALSE);
}
}
/**
* Load specified configuration.
*
* @param is InputStream to the properties file
* @param classLoader for which the configuration will be loaded
*
* @throws IOException If something wrong happens during loading
*/
protected synchronized void readConfiguration(InputStream is, ClassLoader classLoader) throws IOException {
ClassLoaderLogInfo info = classLoaderLoggers.get(classLoader);
try {
info.props.load(is);
} catch (IOException e) {
// Report error
System.err.println("Configuration error");
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException ioe) {
// Ignore
}
}
// Create handlers for the root logger of this classloader
String rootHandlers = info.props.getProperty(".handlers");
String handlers = info.props.getProperty("handlers");
Logger localRootLogger = info.rootNode.logger;
if (handlers != null) {
StringTokenizer tok = new StringTokenizer(handlers, ",");
while (tok.hasMoreTokens()) {
String handlerName = (tok.nextToken().trim());
String handlerClassName = handlerName;
String prefix = "";
if (handlerClassName.length() <= 0) {
continue;
}
// Parse and remove a prefix (prefix start with a digit, such as
// "10WebappFooHandler.")
if (Character.isDigit(handlerClassName.charAt(0))) {
int pos = handlerClassName.indexOf('.');
if (pos >= 0) {
prefix = handlerClassName.substring(0, pos + 1);
handlerClassName = handlerClassName.substring(pos + 1);
}
}
try {
this.prefix.set(prefix);
Handler handler = (Handler) classLoader.loadClass(handlerClassName).getConstructor().newInstance();
// The specification strongly implies all configuration should be done
// during the creation of the handler object.
// This includes setting level, filter, formatter and encoding.
this.prefix.set(null);
info.handlers.put(handlerName, handler);
if (rootHandlers == null) {
localRootLogger.addHandler(handler);
}
} catch (Exception e) {
// Report error
System.err.println("Handler error");
e.printStackTrace();
}
}
}
}
/**
* System property replacement in the given string.
*
* @param str The original string
*
* @return the modified string
*/
protected String replace(String str) {
String result = str;
int pos_start = str.indexOf("${");
if (pos_start >= 0) {
StringBuilder builder = new StringBuilder();
int pos_end = -1;
while (pos_start >= 0) {
builder.append(str, pos_end + 1, pos_start);
pos_end = str.indexOf('}', pos_start + 2);
if (pos_end < 0) {
pos_end = pos_start - 1;
break;
}
String propName = str.substring(pos_start + 2, pos_end);
String replacement = replaceWebApplicationProperties(propName);
if (replacement == null) {
replacement = propName.length() > 0 ? System.getProperty(propName) : null;
}
if (replacement != null) {
builder.append(replacement);
} else {
builder.append(str, pos_start, pos_end + 1);
}
pos_start = str.indexOf("${", pos_end + 1);
}
builder.append(str, pos_end + 1, str.length());
result = builder.toString();
}
return result;
}
private String replaceWebApplicationProperties(String propName) {
ClassLoader cl = getClassLoader();
if (cl instanceof WebappProperties) {
WebappProperties wProps = (WebappProperties) cl;
if ("classloader.webappName".equals(propName)) {
return wProps.getWebappName();
} else if ("classloader.hostName".equals(propName)) {
return wProps.getHostName();
} else if ("classloader.serviceName".equals(propName)) {
return wProps.getServiceName();
} else {
return null;
}
} else {
return null;
}
}
/**
* Obtain the class loader to use to lookup loggers, obtain configuration etc. The search order is:
* <ol>
* <li>Thread.currentThread().getContextClassLoader()</li>
* <li>The class laoder of this class</li>
* </ol>
*
* @return The class loader to use to lookup loggers, obtain configuration etc.
*/
static ClassLoader getClassLoader() {
ClassLoader result = Thread.currentThread().getContextClassLoader();
if (result == null) {
result = ClassLoaderLogManager.class.getClassLoader();
}
return result;
}
// ---------------------------------------------------- LogNode Inner Class
protected static final class LogNode {
Logger logger;
final Map<String, LogNode> children = new HashMap<>();
final LogNode parent;
LogNode(final LogNode parent, final Logger logger) {
this.parent = parent;
this.logger = logger;
}
LogNode(final LogNode parent) {
this(parent, null);
}
LogNode findNode(String name) {
LogNode currentNode = this;
if (logger.getName().equals(name)) {
return this;
}
while (name != null) {
final int dotIndex = name.indexOf('.');
final String nextName;
if (dotIndex < 0) {
nextName = name;
name = null;
} else {
nextName = name.substring(0, dotIndex);
name = name.substring(dotIndex + 1);
}
LogNode childNode = currentNode.children.get(nextName);
if (childNode == null) {
childNode = new LogNode(currentNode);
currentNode.children.put(nextName, childNode);
}
currentNode = childNode;
}
return currentNode;
}
Logger findParentLogger() {
Logger logger = null;
LogNode node = parent;
while (node != null && logger == null) {
logger = node.logger;
node = node.parent;
}
return logger;
}
void setParentLogger(final Logger parent) {
for (final LogNode childNode : children.values()) {
if (childNode.logger == null) {
childNode.setParentLogger(parent);
} else {
childNode.logger.setParent(parent);
}
}
}
}
// -------------------------------------------- ClassLoaderInfo Inner Class
protected static final class ClassLoaderLogInfo {
final LogNode rootNode;
final Map<String, Logger> loggers = new ConcurrentHashMap<>();
final Map<String, Handler> handlers = new HashMap<>();
final Properties props = new Properties();
ClassLoaderLogInfo(final LogNode rootNode) {
this.rootNode = rootNode;
}
}
// ------------------------------------------------- RootLogger Inner Class
/**
* This class is needed to instantiate the root of each per classloader hierarchy.
*/
protected static class RootLogger extends Logger {
public RootLogger() {
super("", null);
}
}
}