Merge branch '3.0.x' into 3.1.x

Closes gh-37920

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/RestartApplicationListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@
 import org.springframework.boot.context.event.ApplicationPreparedEvent;
 import org.springframework.boot.context.event.ApplicationReadyEvent;
 import org.springframework.boot.context.event.ApplicationStartingEvent;
+import org.springframework.boot.devtools.system.DevToolsEnablementDeducer;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationListener;
 import org.springframework.core.Ordered;
@@ -66,7 +67,14 @@ private void onApplicationStartingEvent(ApplicationStartingEvent event) {
 		String enabled = System.getProperty(ENABLED_PROPERTY);
 		RestartInitializer restartInitializer = null;
 		if (enabled == null) {
-			restartInitializer = new DefaultRestartInitializer();
+			if (implicitlyEnableRestart()) {
+				restartInitializer = new DefaultRestartInitializer();
+			}
+			else {
+				logger.info("Restart disabled due to context in which it is running");
+				Restarter.disable();
+				return;
+			}
 		}
 		else if (Boolean.parseBoolean(enabled)) {
 			restartInitializer = new DefaultRestartInitializer() {
@@ -96,6 +104,10 @@ protected boolean isDevelopmentClassLoader(ClassLoader classLoader) {
 		}
 	}
 
+	boolean implicitlyEnableRestart() {
+		return DevToolsEnablementDeducer.shouldEnable(Thread.currentThread());
+	}
+
 	private void onApplicationPreparedEvent(ApplicationPreparedEvent event) {
 		Restarter.getInstance().prepare(event.getApplicationContext());
 	}

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/Restarter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -408,7 +408,7 @@ boolean isFinished() {
 	}
 
 	void prepare(ConfigurableApplicationContext applicationContext) {
-		if (applicationContext != null && applicationContext.getParent() != null) {
+		if (!this.enabled || (applicationContext != null && applicationContext.getParent() != null)) {
 			return;
 		}
 		if (applicationContext instanceof GenericApplicationContext genericContext) {

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/RestartApplicationListenerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,15 +66,15 @@ void isHighestPriority() {
 
 	@Test
 	void initializeWithReady() {
-		testInitialize(false);
+		testInitialize(false, new ImplicitlyEnabledRestartApplicationListener());
 		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("args", ARGS);
 		assertThat(Restarter.getInstance().isFinished()).isTrue();
 		assertThat((List<?>) ReflectionTestUtils.getField(Restarter.getInstance(), "rootContexts")).isNotEmpty();
 	}
 
 	@Test
 	void initializeWithFail() {
-		testInitialize(true);
+		testInitialize(true, new ImplicitlyEnabledRestartApplicationListener());
 		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("args", ARGS);
 		assertThat(Restarter.getInstance().isFinished()).isTrue();
 		assertThat((List<?>) ReflectionTestUtils.getField(Restarter.getInstance(), "rootContexts")).isEmpty();
@@ -83,22 +83,36 @@ void initializeWithFail() {
 	@Test
 	void disableWithSystemProperty(CapturedOutput output) {
 		System.setProperty(ENABLED_PROPERTY, "false");
-		testInitialize(false);
+		testInitialize(false, new ImplicitlyEnabledRestartApplicationListener());
 		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("enabled", false);
 		assertThat(output).contains("Restart disabled due to System property");
 	}
 
 	@Test
 	void enableWithSystemProperty(CapturedOutput output) {
 		System.setProperty(ENABLED_PROPERTY, "true");
-		testInitialize(false);
+		testInitialize(false, new ImplicitlyEnabledRestartApplicationListener());
 		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("enabled", true);
 		assertThat(output).contains("Restart enabled irrespective of application packaging due to System property");
 	}
 
-	private void testInitialize(boolean failed) {
+	@Test
+	void enableWithSystemPropertyWhenImplicitlyDisabled(CapturedOutput output) {
+		System.setProperty(ENABLED_PROPERTY, "true");
+		testInitialize(false, new RestartApplicationListener());
+		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("enabled", true);
+		assertThat(output).contains("Restart enabled irrespective of application packaging due to System property");
+	}
+
+	@Test
+	void implicitlyDisabledInTests(CapturedOutput output) {
+		testInitialize(false, new RestartApplicationListener());
+		assertThat(Restarter.getInstance()).hasFieldOrPropertyWithValue("enabled", false);
+		assertThat(output).contains("Restart disabled due to context in which it is running");
+	}
+
+	private void testInitialize(boolean failed, RestartApplicationListener listener) {
 		Restarter.clearInstance();
-		RestartApplicationListener listener = new RestartApplicationListener();
 		DefaultBootstrapContext bootstrapContext = new DefaultBootstrapContext();
 		SpringApplication application = new SpringApplication();
 		ConfigurableApplicationContext context = mock(ConfigurableApplicationContext.class);
@@ -114,4 +128,13 @@ private void testInitialize(boolean failed) {
 		}
 	}
 
+	private static class ImplicitlyEnabledRestartApplicationListener extends RestartApplicationListener {
+
+		@Override
+		boolean implicitlyEnableRestart() {
+			return true;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/RestarterTests.java

@@ -24,6 +24,7 @@
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import org.assertj.core.api.InstanceOfAssertFactories;
 import org.awaitility.Awaitility;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -37,13 +38,15 @@
 import org.springframework.boot.test.system.CapturedOutput;
 import org.springframework.boot.test.system.OutputCaptureExtension;
 import org.springframework.context.ApplicationListener;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.event.ContextClosedEvent;
 import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
 import org.springframework.util.StringUtils;
 
+import static org.assertj.core.api.Assertions.as;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
@@ -90,6 +93,14 @@ void testRestart(CapturedOutput output) {
 		});
 	}
 
+	@Test
+	void testDisabled() {
+		Restarter.disable();
+		ConfigurableApplicationContext context = mock(ConfigurableApplicationContext.class);
+		Restarter.getInstance().prepare(context);
+		assertThat(Restarter.getInstance()).extracting("rootContexts", as(InstanceOfAssertFactories.LIST)).isEmpty();
+	}
+
 	@Test
 	@SuppressWarnings("rawtypes")
 	void getOrAddAttributeWithNewAttribute() {