Polish

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplicationRunListeners.java

@@ -19,6 +19,7 @@ package org.springframework.boot;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.function.Consumer;
 
 import org.apache.commons.logging.Log;
 
@@ -49,59 +50,36 @@ class SpringApplicationRunListeners {
 	}
 
 	void starting() {
-		StartupStep starting = this.applicationStartup.start("spring.boot.application.starting");
+		doWithListeners("spring.boot.application.starting", SpringApplicationRunListener::starting);
-		for (SpringApplicationRunListener listener : this.listeners) {
-			listener.starting();
-		}
-		starting.end();
 	}
 
 	void environmentPrepared(ConfigurableEnvironment environment) {
-		StartupStep environmentPrepared = this.applicationStartup.start("spring.boot.application.environment-prepared");
+		doWithListeners("spring.boot.application.environment-prepared",
-		for (SpringApplicationRunListener listener : this.listeners) {
+				(listener) -> listener.environmentPrepared(environment));
-			listener.environmentPrepared(environment);
-		}
-		environmentPrepared.end();
 	}
 
 	void contextPrepared(ConfigurableApplicationContext context) {
-		StartupStep contextPrepared = this.applicationStartup.start("spring.boot.application.context-prepared");
+		doWithListeners("spring.boot.application.context-prepared", (listener) -> listener.contextPrepared(context));
-		for (SpringApplicationRunListener listener : this.listeners) {
-			listener.contextPrepared(context);
-		}
-		contextPrepared.end();
 	}
 
 	void contextLoaded(ConfigurableApplicationContext context) {
-		StartupStep contextLoaded = this.applicationStartup.start("spring.boot.application.context-loaded");
+		doWithListeners("spring.boot.application.context-loaded", (listener) -> listener.contextLoaded(context));
-		for (SpringApplicationRunListener listener : this.listeners) {
-			listener.contextLoaded(context);
-		}
-		contextLoaded.end();
 	}
 
 	void started(ConfigurableApplicationContext context) {
-		StartupStep started = this.applicationStartup.start("spring.boot.application.started");
+		doWithListeners("spring.boot.application.started", (listener) -> listener.started(context));
-		for (SpringApplicationRunListener listener : this.listeners) {
-			listener.started(context);
-		}
-		started.end();
 	}
 
 	void running(ConfigurableApplicationContext context) {
-		StartupStep running = this.applicationStartup.start("spring.boot.application.running");
+		doWithListeners("spring.boot.application.running", (listener) -> listener.running(context));
-		for (SpringApplicationRunListener listener : this.listeners) {
-			listener.running(context);
-		}
-		running.end();
 	}
 
 	void failed(ConfigurableApplicationContext context, Throwable exception) {
-		StartupStep failed = this.applicationStartup.start("spring.boot.application.failed");
+		doWithListeners("spring.boot.application.failed",
-		for (SpringApplicationRunListener listener : this.listeners) {
+				(listener) -> callFailedListener(listener, context, exception), (step) -> {
-			callFailedListener(listener, context, exception);
+					step.tag("exception", exception.getClass().toString());
-		}
+					step.tag("message", exception.getMessage());
-		failed.tag("exception", exception.getClass().toString()).tag("message", exception.getMessage()).end();
+				});
 	}
 
 	private void callFailedListener(SpringApplicationRunListener listener, ConfigurableApplicationContext context,
@@ -124,4 +102,16 @@ class SpringApplicationRunListeners {
 		}
 	}
 
+	private void doWithListeners(String stepName, Consumer<SpringApplicationRunListener> listenerAction) {
+		doWithListeners(stepName, listenerAction, StartupStep::end);
+	}
+
+	private void doWithListeners(String stepName, Consumer<SpringApplicationRunListener> listenerAction,
+			Consumer<StartupStep> stepAction) {
+		StartupStep step = this.applicationStartup.start(stepName);
+		this.listeners.forEach(listenerAction);
+		stepAction.accept(step);
+		step.end();
+	}
+
 }

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

@@ -58,24 +58,20 @@ public abstract class LoggingSystem {
 	 */
 	public static final String ROOT_LOGGER_NAME = "ROOT";
 
-	private static final Function<ClassLoader, LoggingSystem> SYSTEM_FACTORY;
+	private static final Function<ClassLoader, LoggingSystem> SYSTEM_FACTORY = getSystemFactory();
 
-	static {
+	private static Function<ClassLoader, LoggingSystem> getSystemFactory() {
 		ClassLoader classLoader = LoggingSystem.class.getClassLoader();
 		if (ClassUtils.isPresent("ch.qos.logback.core.Appender", classLoader)) {
-			SYSTEM_FACTORY = (cl) -> new LogbackLoggingSystem(cl);
+			return LogbackLoggingSystem::new;
 		}
-		else if (ClassUtils.isPresent("org.apache.logging.log4j.core.impl.Log4jContextFactory", classLoader)) {
+		if (ClassUtils.isPresent("org.apache.logging.log4j.core.impl.Log4jContextFactory", classLoader)) {
-			SYSTEM_FACTORY = (cl) -> new Log4J2LoggingSystem(cl);
+			return Log4J2LoggingSystem::new;
 		}
-		else if (ClassUtils.isPresent("java.util.logging.LogManager", classLoader)) {
+		if (ClassUtils.isPresent("java.util.logging.LogManager", classLoader)) {
-			SYSTEM_FACTORY = (cl) -> new JavaLoggingSystem(cl);
+			return JavaLoggingSystem::new;
-		}
-		else {
-			SYSTEM_FACTORY = (cl) -> {
-				throw new IllegalStateException("No suitable logging system located");
-			};
 		}
+		throw new IllegalStateException("No suitable logging system located");
 	}
 
 	/**

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/SpringApplicationTests.java

@@ -1160,12 +1160,10 @@ class SpringApplicationTests {
 		given(applicationStartup.start(anyString())).willReturn(startupStep);
 		given(startupStep.tag(anyString(), anyString())).willReturn(startupStep);
 		given(startupStep.tag(anyString(), ArgumentMatchers.<Supplier<String>>any())).willReturn(startupStep);
-
 		SpringApplication application = new SpringApplication(ExampleConfig.class);
 		application.setWebApplicationType(WebApplicationType.NONE);
 		application.setApplicationStartup(applicationStartup);
 		this.context = application.run();
-
 		assertThat(this.context.getBean(ApplicationStartup.class)).isEqualTo(applicationStartup);
 		verify(applicationStartup).start("spring.boot.application.starting");
 		verify(applicationStartup).start("spring.boot.application.environment-prepared");