SOLR-18107: Test fix testLogLevelHandlerOutput (#4146)

Author: dsmiley

solr/core/src/test/org/apache/solr/handler/admin/LoggingHandlerTest.java

@@ -21,6 +21,7 @@
 import java.util.Map;
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.solr.SolrTestCaseJ4;
@@ -66,9 +67,16 @@ public void testLogLevelHandlerOutput() throws Exception {
 
     final Configuration config = ctx.getConfiguration();
 
+    // Create and hold strong references to loggers to prevent GC from removing them
+    // during test execution (Log4j2 uses weak references internally)
+    Logger parentLogger = LogManager.getLogger(PARENT_LOGGER_NAME);
+    Logger aLogger = LogManager.getLogger(A_LOGGER_NAME);
+    Logger bLogger = LogManager.getLogger(B_LOGGER_NAME);
+    Logger bxLogger = LogManager.getLogger(BX_LOGGER_NAME);
+
     { // sanity check our setup...
 
-      // did anybody break the anotations?
+      // did anybody break the annotations?
       assertNotNull(this.getClass().getAnnotation(LogLevel.class));
       final String annotationConfig = this.getClass().getAnnotation(LogLevel.class).value();
       assertTrue("WTF: " + annotationConfig, annotationConfig.startsWith(PARENT_LOGGER_NAME));
@@ -88,11 +96,11 @@ public void testLogLevelHandlerOutput() throws Exception {
             config.getLoggerConfig(logger));
       }
 
-      // Either explicit, or inherited, effictive logger values...
-      for (String logger :
-          Arrays.asList(PARENT_LOGGER_NAME, A_LOGGER_NAME, B_LOGGER_NAME, BX_LOGGER_NAME)) {
-        assertEquals(Level.DEBUG, LogManager.getLogger(logger).getLevel());
-      }
+      // Either explicit, or inherited, effective logger values...
+      assertEquals(Level.DEBUG, parentLogger.getLevel());
+      assertEquals(Level.DEBUG, aLogger.getLevel());
+      assertEquals(Level.DEBUG, bLogger.getLevel());
+      assertEquals(Level.DEBUG, bxLogger.getLevel());
     }
 
     SolrClient client = new EmbeddedSolrServer(h.getCore());
@@ -130,18 +138,18 @@ public void testLogLevelHandlerOutput() throws Exception {
       assertLoggerLevel(updatedLoggerLevel, B_LOGGER_NAME, "TRACE", true);
       assertLoggerLevel(updatedLoggerLevel, BX_LOGGER_NAME, "TRACE", false);
 
-      // check directly with log4j what it's (updated) config has...
+      // check directly with log4j what its (updated) config has...
       assertEquals(Level.DEBUG, config.getLoggerConfig(PARENT_LOGGER_NAME).getExplicitLevel());
       assertEquals(Level.TRACE, config.getLoggerConfig(B_LOGGER_NAME).getExplicitLevel());
       assertEquals(
           "Unexpected config for BX ... expected B's config",
           config.getLoggerConfig(B_LOGGER_NAME),
           config.getLoggerConfig(BX_LOGGER_NAME));
-      // ...and what it's effective values
-      assertEquals(Level.DEBUG, LogManager.getLogger(PARENT_LOGGER_NAME).getLevel());
-      assertEquals(Level.DEBUG, LogManager.getLogger(A_LOGGER_NAME).getLevel());
-      assertEquals(Level.TRACE, LogManager.getLogger(B_LOGGER_NAME).getLevel());
-      assertEquals(Level.TRACE, LogManager.getLogger(BX_LOGGER_NAME).getLevel());
+      // ...and what its effective values are
+      assertEquals(Level.DEBUG, parentLogger.getLevel());
+      assertEquals(Level.DEBUG, aLogger.getLevel());
+      assertEquals(Level.TRACE, bLogger.getLevel());
+      assertEquals(Level.TRACE, bxLogger.getLevel());
     }
 
     { // UNSET
@@ -161,7 +169,7 @@ public void testLogLevelHandlerOutput() throws Exception {
       assertLoggerLevel(removedLoggerLevel, B_LOGGER_NAME, "DEBUG", false);
       assertLoggerLevel(removedLoggerLevel, BX_LOGGER_NAME, "DEBUG", false);
 
-      // check directly with log4j what it's (updated) config has...
+      // check directly with log4j what its (updated) config has...
       //
       // NOTE: LoggingHandler must not actually "remove" the LoggerConfig for B on 'unset'
       // (it might have already been defined in log4j's original config for some other reason,
@@ -176,11 +184,11 @@ public void testLogLevelHandlerOutput() throws Exception {
           "Unexpected config for BX ... expected B's config",
           config.getLoggerConfig(B_LOGGER_NAME),
           config.getLoggerConfig(BX_LOGGER_NAME));
-      // ...and what it's effective values
-      assertEquals(Level.DEBUG, LogManager.getLogger(PARENT_LOGGER_NAME).getLevel());
-      assertEquals(Level.DEBUG, LogManager.getLogger(A_LOGGER_NAME).getLevel());
-      assertEquals(Level.DEBUG, LogManager.getLogger(B_LOGGER_NAME).getLevel());
-      assertEquals(Level.DEBUG, LogManager.getLogger(BX_LOGGER_NAME).getLevel());
+      // ...and what its effective values are
+      assertEquals(Level.DEBUG, parentLogger.getLevel());
+      assertEquals(Level.DEBUG, aLogger.getLevel());
+      assertEquals(Level.DEBUG, bLogger.getLevel());
+      assertEquals(Level.DEBUG, bxLogger.getLevel());
     }
   }