Use nanosecond precision for LogEvent comparison

Compare LogEvent instances using getInstant().getNanoOfMillisecond() instead of getTimeMillis() by adding a helper method. Add a unit test (testAppendTransferAndStopClearsEvents) to verify InMemoryAppender.transfer() behavior, that events are not duplicated and stop() clears buffered events. Also import SimpleMessage and update test event creation to use the imported type.

Author: mercyblitz

microsphere-log4j2/src/main/java/io/microsphere/logging/log4j2/LogEventComparator.java

@@ -39,6 +39,10 @@ private LogEventComparator() {
 
     @Override
     public int compare(LogEvent o1, LogEvent o2) {
-        return Long.compare(o1.getTimeMillis(), o2.getTimeMillis());
+        return Long.compare(getNanoOfMillisecond(o1), getNanoOfMillisecond(o2));
+    }
+
+    private int getNanoOfMillisecond(LogEvent logEvent) {
+        return logEvent.getInstant().getNanoOfMillisecond();
     }
 }

microsphere-log4j2/src/test/java/io/microsphere/logging/log4j2/appender/InMemoryAppenderTest.java

@@ -21,6 +21,7 @@
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.impl.Log4jLogEvent;
 import org.apache.logging.log4j.core.layout.PatternLayout;
+import org.apache.logging.log4j.message.SimpleMessage;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -61,6 +62,34 @@ void testBasicMethodsAndLifecycle() {
         appender.stop(); // also covers clear() on empty set
     }
 
+    @Test
+    void testAppendTransferAndStopClearsEvents() {
+        InMemoryAppender source = new InMemoryAppender();
+        CollectingAppender target = new CollectingAppender();
+
+        LogEvent event1 = newEvent("message-1");
+        LogEvent event2 = newEvent("message-2");
+
+        source.append(event1);
+        source.append(event2);
+
+        source.transfer(target);
+
+        assertEquals(2, target.events.size());
+        assertTrue(target.events.contains(event1));
+        assertTrue(target.events.contains(event2));
+
+        // Verify source is emptied after transfer
+        source.transfer(target);
+        assertEquals(2, target.events.size(), "second transfer should not add duplicates");
+
+        // Re-add and ensure stop clears buffered events
+        source.append(newEvent("message-3"));
+        source.stop();
+        source.transfer(target);
+        assertEquals(2, target.events.size(), "stop() should clear pending events");
+    }
+
     @Test
     void testFindInMemoryAppenderWithoutConfiguration() {
         // In plain unit test context, this may be null unless explicitly configured.
@@ -75,7 +104,7 @@ private static LogEvent newEvent(String message) {
                 .setLoggerName("test.logger")
                 .setLoggerFqcn(InMemoryAppenderTest.class.getName())
                 .setLevel(INFO)
-                .setMessage(new org.apache.logging.log4j.message.SimpleMessage(message))
+                .setMessage(new SimpleMessage(message))
                 .build();
     }