Move to kernel style SPDX license identifiers

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-log4j / org / lttng / ust / agent / log4j / LttngLog4jAgent.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java b/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
index 6cb74f91b5516864c1cc35403a1e8ff525cdda38..bb5deb351fe858995b28038dd151bc7d48076574 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
@@ -1,28 +1,21 @@
 /*
- * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License, version 2.1 only,
- * as published by the Free Software Foundation.
- *
- * This library is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Copyright (C) 2015 EfficiOS Inc.
+ * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
  */
 
 package org.lttng.ust.agent.log4j;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Enumeration;
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
 
 import org.apache.log4j.Appender;
+import org.apache.log4j.Category;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
 import org.lttng.ust.agent.AbstractLttngAgent;
@@ -50,7 +43,7 @@ class LttngLog4jAgent extends AbstractLttngAgent<LttngLogAppender> {
 
        @Override
        public Collection<String> listAvailableEvents() {
-               List<String> ret = new ArrayList<String>();
+               Set<String> ret = new TreeSet<String>();
 
                @SuppressWarnings("unchecked")
                List<Logger> loggers = Collections.list(LogManager.getCurrentLoggers());
@@ -71,14 +64,32 @@ class LttngLog4jAgent extends AbstractLttngAgent<LttngLogAppender> {
                return ret;
        }
 
-       private static boolean hasLttngAppenderAttached(Logger logger) {
+       private static boolean hasLttngAppenderAttached(Category logger) {
                @SuppressWarnings("unchecked")
-               List<Appender> appenders = Collections.list(logger.getAllAppenders());
-               for (Appender appender : appenders) {
-                       if (appender instanceof LttngLogAppender) {
-                               return true;
+               Enumeration<Appender> appenders = logger.getAllAppenders();
+               if (appenders != null) {
+                       for (Appender appender : Collections.list(appenders)) {
+                               if (appender instanceof LttngLogAppender) {
+                                       return true;
+                               }
                        }
                }
+
+               /*
+                * A parent logger, if any, may be connected to an LTTng handler. In
+                * this case, we will want to include this child logger in the output,
+                * since it will be accessible by LTTng.
+                */
+               Category parent = logger.getParent();
+               if (parent != null) {
+                       return hasLttngAppenderAttached(parent);
+               }
+
+               /*
+                * We have reached the root logger and have not found any LTTng handler,
+                * this event will not be accessible.
+                */
                return false;
        }
+
 }