Close GelfSender on Appender lifecycle termination #243

GelfLogAppender now overrides the proper lifecycle method to intercept the stop() signal.

src/main/java/biz/paluch/logging/gelf/log4j2/GelfLogAppender.java

@@ -4,6 +4,7 @@
 import static org.apache.logging.log4j.core.layout.PatternLayout.newBuilder;
 
 import java.util.Collections;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.core.Filter;
@@ -375,19 +376,23 @@ public void reportError(String message, Exception exception) {
     }
 
     @Override
-    public void stop() {
+    protected boolean stop(long timeout, TimeUnit timeUnit, boolean changeLifeCycleState) {
+
         if (null != gelfSender) {
             Closer.close(gelfSender);
             gelfSender = null;
         }
-        super.stop();
+
+        return super.stop(timeout, timeUnit, changeLifeCycleState);
     }
 
     @Override
     public void start() {
+
         if (null == gelfSender) {
             gelfSender = createGelfSender();
         }
+
         super.start();
     }
 

src/test/java/biz/paluch/logging/gelf/log4j2/GelfLogAppenderUnitTests.java

@@ -0,0 +1,45 @@
+package biz.paluch.logging.gelf.log4j2;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.Test;
+
+import biz.paluch.logging.gelf.MdcGelfMessageAssembler;
+import biz.paluch.logging.gelf.intern.GelfSender;
+
+/**
+ * Unit tests for {@link GelfLogAppender}.
+ * 
+ * @author Mark Paluch
+ */
+class GelfLogAppenderUnitTests {
+
+    @Test
+    void testStop() {
+
+        GelfSender sender = mock(GelfSender.class);
+
+        GelfLogAppender sut = new GelfLogAppender("name", null, new MdcGelfMessageAssembler(), true);
+        sut.gelfSender = sender;
+
+        sut.stop();
+
+        verify(sender).close();
+    }
+
+    @Test
+    void testStopWithTimeout() {
+
+        GelfSender sender = mock(GelfSender.class);
+
+        GelfLogAppender sut = new GelfLogAppender("name", null, new MdcGelfMessageAssembler(), true);
+        sut.gelfSender = sender;
+
+        sut.stop(0, TimeUnit.SECONDS);
+
+        verify(sender).close();
+    }
+}