Support @order on [CommandLine|Application]Runner @bean definitions

Prior to this commit, `@Order` annotation on `@Bean` method was not
considered for `CommandLineRunner` and `ApplicationRunner`.

This commit introduces a `Runner` marker interface and uses it to
retrieve the runner beans. As a result, it enables the use of `@Order`
annotations on `@Bean` methods for both `CommandLineRunner` and
`ApplicationRunner`.

Signed-off-by: Tadaya Tsuyukubo <tadaya@ttddyy.net>

See gh-37905

Author: ttddyy

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

@@ -30,7 +30,7 @@
  * @see CommandLineRunner
  */
 @FunctionalInterface
-public interface ApplicationRunner {
+public interface ApplicationRunner extends Runner {
 
 	/**
 	 * Callback used to run the bean.

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

@@ -33,7 +33,7 @@
  * @see ApplicationRunner
  */
 @FunctionalInterface
-public interface CommandLineRunner {
+public interface CommandLineRunner extends Runner {
 
 	/**
 	 * Callback used to run the bean.

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

@@ -0,0 +1,28 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot;
+
+/**
+ * Marker interface for runners.
+ *
+ * @author Tadaya Tsuyukubo
+ * @see ApplicationRunner
+ * @see CommandLineRunner
+ */
+interface Runner {
+
+}

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

@@ -156,6 +156,7 @@
  * @author Brian Clozel
  * @author Ethan Rubinson
  * @author Chris Bono
+ * @author Tadaya Tsuyukubo
  * @since 1.0.0
  * @see #run(Class, String[])
  * @see #run(Class[], String[])
@@ -740,18 +741,14 @@ protected void afterRefresh(ConfigurableApplicationContext context, ApplicationA
 	}
 
 	private void callRunners(ApplicationContext context, ApplicationArguments args) {
-		List<Object> runners = new ArrayList<>();
-		runners.addAll(context.getBeansOfType(ApplicationRunner.class).values());
-		runners.addAll(context.getBeansOfType(CommandLineRunner.class).values());
-		AnnotationAwareOrderComparator.sort(runners);
-		for (Object runner : new LinkedHashSet<>(runners)) {
+		context.getBeanProvider(Runner.class).orderedStream().forEach((runner) -> {
 			if (runner instanceof ApplicationRunner) {
 				callRunner((ApplicationRunner) runner, args);
 			}
 			if (runner instanceof CommandLineRunner) {
 				callRunner((CommandLineRunner) runner, args);
 			}
-		}
+		});
 	}
 
 	private void callRunner(ApplicationRunner runner, ApplicationArguments args) {

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

@@ -95,6 +95,7 @@
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
 import org.springframework.core.env.CommandLinePropertySource;
 import org.springframework.core.env.CompositePropertySource;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -154,6 +155,7 @@
  * @author Nguyen Bao Sach
  * @author Chris Bono
  * @author Brian Clozel
+ * @author Tadaya Tsuyukubo
  */
 @ExtendWith(OutputCaptureExtension.class)
 class SpringApplicationTests {
@@ -667,6 +669,15 @@ void runCommandLineRunnersAndApplicationRunners() {
 		assertThat(this.context).has(runTestRunnerBean("runnerC"));
 	}
 
+	@Test
+	void runFunctionalCommandLineRunnersAndApplicationRunners() {
+		SpringApplication application = new SpringApplication(FunctionalRunnerConfig.class);
+		application.setWebApplicationType(WebApplicationType.NONE);
+		this.context = application.run("arg");
+		FunctionalRunnerConfig config = this.context.getBean(FunctionalRunnerConfig.class);
+		assertThat(config.runners).containsExactly("runnerA", "runnerB", "runnerC");
+	}
+
 	@Test
 	@SuppressWarnings("unchecked")
 	void runnersAreCalledAfterStartedIsLoggedAndBeforeApplicationReadyEventIsPublished(CapturedOutput output)
@@ -1573,6 +1584,31 @@ TestCommandLineRunner runnerA() {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class FunctionalRunnerConfig {
+
+		List<String> runners = new ArrayList<>();
+
+		@Bean
+		@Order // default is LOWEST_PRECEDENCE
+		CommandLineRunner runnerC() {
+			return (args) -> this.runners.add("runnerC");
+		}
+
+		@Bean
+		@Order(Ordered.LOWEST_PRECEDENCE - 1)
+		ApplicationRunner runnerB() {
+			return (args) -> this.runners.add("runnerB");
+		}
+
+		@Bean
+		@Order(Ordered.HIGHEST_PRECEDENCE)
+		CommandLineRunner runnerA() {
+			return (args) -> this.runners.add("runnerA");
+		}
+
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class ExitCodeCommandLineRunConfig {