+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-only
- *
- * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
- */
-
-package org.lttng.ust.agent;
-
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.util.logging.Handler;
-import java.util.logging.Logger;
-
-/**
- * The central agent managing the JUL and Log4j handlers.
- *
- * @author David Goulet
- * @deprecated Applications are now expected to manage their Logger and Handler
- * objects.
- */
-@Deprecated
-public class LTTngAgent {
-
- private static LTTngAgent instance = null;
-
- /**
- * Public getter to acquire a reference to this singleton object.
- *
- * @return The agent instance
- */
- public static synchronized LTTngAgent getLTTngAgent() {
- if (instance == null) {
- instance = new LTTngAgent();
- }
- return instance;
- }
-
- /**
- * Dispose the agent. Applications should call this once they are done
- * logging. This dispose function is non-static for backwards
- * compatibility purposes.
- */
- @SuppressWarnings("static-method")
- public void dispose() {
- synchronized (LTTngAgent.class) {
- if (instance != null) {
- instance.disposeInstance();
- instance = null;
- }
- }
- return;
- }
-
- private ILttngHandler julHandler = null;
- private ILttngHandler log4jAppender = null;
-
- /**
- * Private constructor. This is a singleton and a reference should be
- * acquired using {@link #getLTTngAgent()}.
- */
- private LTTngAgent() {
- initJulHandler();
- initLog4jAppender();
- }
-
- /**
- * "Destructor" method.
- */
- private void disposeInstance() {
- disposeJulHandler();
- disposeLog4jAppender();
- }
-
- /**
- * Create a LTTng-JUL handler, and attach it to the JUL root logger.
- */
- private void initJulHandler() {
- try {
- Class<?> julHandlerClass = Class.forName("org.lttng.ust.agent.jul.LttngLogHandler");
- /*
- * It is safer to use Constructor.newInstance() rather than
- * Class.newInstance(), because it will catch the exceptions thrown
- * by the constructor below (which happens if the Java library is
- * present, but the matching JNI one is not).
- */
- Constructor<?> julHandlerCtor = julHandlerClass.getConstructor();
- julHandler = (ILttngHandler) julHandlerCtor.newInstance();
-
- /* Attach the handler to the root JUL logger */
- Logger.getLogger("").addHandler((Handler) julHandler);
-
- /*
- * If any of the following exceptions happen, it means we could not
- * find or initialize LTTng JUL classes. We will not setup LTTng JUL
- * tracing in this case.
- */
- } catch (SecurityException e) {
- } catch (IllegalAccessException e) {
- } catch (IllegalArgumentException e) {
- } catch (ClassNotFoundException e) {
- } catch (NoSuchMethodException e) {
- } catch (InstantiationException e) {
- } catch (InvocationTargetException e) {
- }
- }
-
- /**
- * Create a LTTng-logj4 appender, and attach it to the log4j root logger.
- */
- private void initLog4jAppender() {
- /*
- * Since Log4j is a 3rd party library, we first need to check if we can
- * load any of its classes.
- */
- if (!testLog4jClasses()) {
- return;
- }
-
- try {
- Class<?> log4jAppenderClass = Class.forName("org.lttng.ust.agent.log4j.LttngLogAppender");
- Constructor<?> log4jAppendCtor = log4jAppenderClass.getConstructor();
- log4jAppender = (ILttngHandler) log4jAppendCtor.newInstance();
-
- /*
- * If any of the following exceptions happen, it means we could not
- * find or initialize LTTng log4j classes. We will not setup LTTng
- * log4j tracing in this case.
- */
- } catch (SecurityException e) {
- return;
- } catch (ClassNotFoundException e) {
- return;
- } catch (NoSuchMethodException e) {
- return;
- } catch (IllegalArgumentException e) {
- return;
- } catch (InstantiationException e) {
- return;
- } catch (IllegalAccessException e) {
- return;
- } catch (InvocationTargetException e) {
- return;
- }
-
- /*
- * Attach the appender to the root Log4j logger. Slightly more tricky
- * here, as log4j.Logger is not in the base Java library, and we do not
- * want the "common" package to depend on log4j. So we have to obtain it
- * through reflection too.
- */
- try {
- Class<?> loggerClass = Class.forName("org.apache.log4j.Logger");
- Class<?> appenderClass = Class.forName("org.apache.log4j.Appender");
-
- Method getRootLoggerMethod = loggerClass.getMethod("getRootLogger", (Class<?>[]) null);
- Method addAppenderMethod = loggerClass.getMethod("addAppender", appenderClass);
-
- Object rootLogger = getRootLoggerMethod.invoke(null, (Object[]) null);
- addAppenderMethod.invoke(rootLogger, log4jAppender);
-
- /*
- * We have checked for the log4j library version previously, none of
- * the following exceptions should happen.
- */
- } catch (SecurityException e) {
- throw new IllegalStateException(e);
- } catch (ClassNotFoundException e) {
- throw new IllegalStateException(e);
- } catch (NoSuchMethodException e) {
- throw new IllegalStateException(e);
- } catch (IllegalArgumentException e) {
- throw new IllegalStateException(e);
- } catch (IllegalAccessException e) {
- throw new IllegalStateException(e);
- } catch (InvocationTargetException e) {
- throw new IllegalStateException(e);
- }
- }
-
- /**
- * Check if log4j >= 1.2.15 library is present.
- */
- private static boolean testLog4jClasses() {
- Class<?> loggingEventClass;
-
- try {
- loggingEventClass = Class.forName("org.apache.log4j.spi.LoggingEvent");
- } catch (ClassNotFoundException e) {
- /*
- * Log4j classes not found, no need to create the relevant objects
- */
- return false;
- }
-
- /*
- * Detect capabilities of the log4j library. We only support log4j >=
- * 1.2.15. The getTimeStamp() method was introduced in log4j 1.2.15, so
- * verify that it is available.
- *
- * We can't rely on the getPackage().getImplementationVersion() call
- * that would retrieves information from the manifest file found in the
- * JAR since the manifest file shipped from upstream is known to be
- * broken in several versions of the library.
- *
- * More info: https://issues.apache.org/bugzilla/show_bug.cgi?id=44370
- */
- try {
- loggingEventClass.getDeclaredMethod("getTimeStamp");
- } catch (NoSuchMethodException e) {
- System.err.println(
- "Warning: The loaded log4j library is too old. Log4j tracing with LTTng will be disabled.");
- return false;
- } catch (SecurityException e) {
- return false;
- }
-
- return true;
- }
-
- /**
- * Detach the JUL handler from its logger and close it.
- */
- private void disposeJulHandler() {
- if (julHandler == null) {
- /* The JUL handler was not activated, we have nothing to do */
- return;
- }
- Logger.getLogger("").removeHandler((Handler) julHandler);
- julHandler.close();
- julHandler = null;
- }
-
- /**
- * Detach the log4j appender from its logger and close it.
- */
- private void disposeLog4jAppender() {
- if (log4jAppender == null) {
- /* The log4j appender was not active, we have nothing to do */
- return;
- }
-
- /*
- * Detach the appender from the log4j root logger. Again, we have to do
- * this via reflection.
- */
- try {
- Class<?> loggerClass = Class.forName("org.apache.log4j.Logger");
- Class<?> appenderClass = Class.forName("org.apache.log4j.Appender");
-
- Method getRootLoggerMethod = loggerClass.getMethod("getRootLogger", (Class<?>[]) null);
- Method removeAppenderMethod = loggerClass.getMethod("removeAppender", appenderClass);
-
- Object rootLogger = getRootLoggerMethod.invoke(null, (Object[]) null);
- removeAppenderMethod.invoke(rootLogger, log4jAppender);
-
- /*
- * We were able to attach the appender previously, we should not
- * have problems here either!
- */
- } catch (SecurityException e) {
- throw new IllegalStateException(e);
- } catch (ClassNotFoundException e) {
- throw new IllegalStateException(e);
- } catch (NoSuchMethodException e) {
- throw new IllegalStateException(e);
- } catch (IllegalArgumentException e) {
- throw new IllegalStateException(e);
- } catch (IllegalAccessException e) {
- throw new IllegalStateException(e);
- } catch (InvocationTargetException e) {
- throw new IllegalStateException(e);
- }
-
- /* Close the appender */
- log4jAppender.close();
- log4jAppender = null;
- }
-
-}
projects / lttng-ust.git / blobdiff