Polish "Debug mode is not logging web and sql related loggers"

Closes gh-16018

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/logging/LoggingApplicationListener.java

@@ -21,7 +21,6 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.apache.commons.logging.Log;
@@ -321,8 +320,7 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 	}
 
 	protected void initializeLogLevel(LoggingSystem system, LogLevel level) {
-		Optional.ofNullable(LOG_LEVEL_LOGGERS.get(level)).orElse(Collections.emptyList())
-				.stream()
+		LOG_LEVEL_LOGGERS.getOrDefault(level, Collections.emptyList()).stream()
 				.flatMap((logger) -> DEFAULT_GROUP_LOGGERS
 						.getOrDefault(logger, Collections.singletonList(logger)).stream())
 				.forEach((logger) -> system.setLogLevel(logger, level));

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/logging/LoggingApplicationListenerTests.java

@@ -264,15 +264,12 @@ public class LoggingApplicationListenerTests {
 
 	@Test
 	public void parseDebugArgExpandGroups() {
-		addPropertiesToEnvironment(this.context, "debug");
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.context, "debug");
 		this.initializer.initialize(this.context.getEnvironment(),
 				this.context.getClassLoader());
-		ch.qos.logback.classic.Logger sqlGroup = this.loggerContext
-				.getLogger("org.hibernate.SQL");
-		ch.qos.logback.classic.Logger webGroup = this.loggerContext
-				.getLogger("org.springframework.boot.actuate.endpoint.web");
-		webGroup.debug("testdebugwebgroup");
-		sqlGroup.debug("testdebugsqlgroup");
+		this.logFactory.getInstance("org.springframework.boot.actuate.endpoint.web")
+				.debug("testdebugwebgroup");
+		this.logFactory.getInstance("org.hibernate.SQL").debug("testdebugsqlgroup");
 		assertThat(this.outputCapture.toString()).contains("testdebugwebgroup");
 		assertThat(this.outputCapture.toString()).contains("testdebugsqlgroup");
 	}