Move liblttng-ust-java* to 'src/lib/'

[lttng-ust.git] / src / lib / lttng-ust-java-agent / java / lttng-ust-agent-common / org / lttng / ust / agent / utils / LttngUstAgentLogger.java

diff --git a/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/utils/LttngUstAgentLogger.java b/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/utils/LttngUstAgentLogger.java
new file mode 100644 (file)
index 0000000..3e78553
--- /dev/null
+++ b/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/utils/LttngUstAgentLogger.java
@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2016 EfficiOS Inc.
+ * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com>
+ */
+
+package org.lttng.ust.agent.utils;
+
+/**
+ * Logging infrastructure for the lttng-ust Java agent. It prints log messages
+ * to stderr but only when the environment variable LTTNG_UST_DEBUG is defined.
+ *
+ * @author Alexandre Montplaisir
+ */
+public class LttngUstAgentLogger {
+
+       private static final String ENV_VAR_NAME = "LTTNG_UST_DEBUG";
+       private static final boolean LOGGING_ENABLED = (System.getenv(ENV_VAR_NAME) == null ? false : true);
+
+       /**
+        * Log event. Will be printed to stderr if the environment variable
+        * "LTTNG_UST_DEBUG" is defined.
+        *
+        * @param c
+        *            The class logging the message (should normally be called with
+        *            {@link #getClass()}).
+        * @param message
+        *            The message to print
+        */
+       public static void log(Class<?> c, String message) {
+               if (LOGGING_ENABLED) {
+                       System.err.println(c.getSimpleName() + ": " + message);
+               }
+       }
+}