liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/utils/LttngUstAgentLogger.java

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2016 EfficiOS Inc.
   5  * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com>
   6  */
   7
   8 package org.lttng.ust.agent.utils;
   9
  10 /**
  11  * Logging infrastructure for the lttng-ust Java agent. It prints log messages
  12  * to stderr but only when the environment variable LTTNG_UST_DEBUG is defined.
  13  *
  14  * @author Alexandre Montplaisir
  15  */
  16 public class LttngUstAgentLogger {
  17
  18         private static final String ENV_VAR_NAME = "LTTNG_UST_DEBUG";
  19         private static final boolean LOGGING_ENABLED = (System.getenv(ENV_VAR_NAME) == null ? false : true);
  20
  21         /**
  22          * Log event. Will be printed to stderr if the environment variable
  23          * "LTTNG_UST_DEBUG" is defined.
  24          *
  25          * @param c
  26          *            The class logging the message (should normally be called with
  27          *            {@link #getClass()}).
  28          * @param message
  29          *            The message to print
  30          */
  31         public static void log(Class<?> c, String message) {
  32                 if (LOGGING_ENABLED) {
  33                         System.err.println(c.getSimpleName() + ": " + message);
  34                 }
  35         }
  36 }