Polish contribution

See gh-27818

spring-aop/src/main/java/org/springframework/aop/interceptor/AsyncExecutionAspectSupport.java

@@ -43,7 +43,6 @@ import org.springframework.core.task.support.TaskExecutorAdapter;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
-import org.springframework.util.StringValueResolver;
 import org.springframework.util.concurrent.ListenableFuture;
 import org.springframework.util.function.SingletonSupplier;
 
@@ -212,9 +211,8 @@ public abstract class AsyncExecutionAspectSupport implements BeanFactoryAware {
 					" to access qualified executor '" + qualifier + "'");
 		}
 		if (beanFactory instanceof ConfigurableBeanFactory configurableBeanFactory) {
-			StringValueResolver embeddedValueResolver = new EmbeddedValueResolver(configurableBeanFactory);
-			String resolvedValue = embeddedValueResolver.resolveStringValue(qualifier);
-			qualifier = resolvedValue != null ? resolvedValue : "";
+			EmbeddedValueResolver embeddedValueResolver = new EmbeddedValueResolver(configurableBeanFactory);
+			qualifier = embeddedValueResolver.resolveStringValue(qualifier);
 		}
 		return BeanFactoryAnnotationUtils.qualifiedBeanOfType(beanFactory, Executor.class, qualifier);
 	}

spring-context/src/main/java/org/springframework/scheduling/annotation/Async.java

@@ -24,7 +24,8 @@ import java.lang.annotation.Target;
 
 /**
  * Annotation that marks a method as a candidate for <i>asynchronous</i> execution.
- * Can also be used at the type level, in which case all of the type's methods are
+ *
+ * <p>Can also be used at the type level, in which case all of the type's methods are
  * considered as asynchronous. Note, however, that {@code @Async} is not supported
  * on methods declared within a
  * {@link org.springframework.context.annotation.Configuration @Configuration} class.
@@ -41,7 +42,7 @@ import java.lang.annotation.Target;
  * {@code Future} that can be used to track the result of the asynchronous method
  * execution. However, since the target method needs to implement the same signature,
  * it will have to return a temporary {@code Future} handle that just passes a value
- * through: e.g. Spring's {@link AsyncResult}, EJB 3.1's {@link jakarta.ejb.AsyncResult},
+ * through: for example, Spring's {@link AsyncResult}, EJB 3.1's {@link jakarta.ejb.AsyncResult},
  * or {@link java.util.concurrent.CompletableFuture#completedFuture(Object)}.
  *
  * @author Juergen Hoeller
@@ -57,16 +58,18 @@ public @interface Async {
 
 	/**
 	 * A qualifier value for the specified asynchronous operation(s).
-	 * <p>The value support expression such as <code>#{systemProperties.myExecutor}</code>
-	 * or property placeholder such as <code>${my.app.myExecutor}</code>.
 	 * <p>May be used to determine the target executor to be used when executing
 	 * the asynchronous operation(s), matching the qualifier value (or the bean
 	 * name) of a specific {@link java.util.concurrent.Executor Executor} or
 	 * {@link org.springframework.core.task.TaskExecutor TaskExecutor}
 	 * bean definition.
-	 * <p>When specified on a class-level {@code @Async} annotation, indicates that the
+	 * <p>When specified in a class-level {@code @Async} annotation, indicates that the
 	 * given executor should be used for all methods within the class. Method-level use
-	 * of {@code Async#value} always overrides any value set at the class level.
+	 * of {@code Async#value} always overrides any qualifier value configured at
+	 * the class level.
+	 * <p>The qualifier value will be resolved dynamically if supplied as a SpEL
+	 * expression (for example, {@code "#{environment['myExecutor']}"}) or a
+	 * property placeholder (for example, {@code "${my.app.myExecutor}"}).
 	 * @since 3.1.2
 	 */
 	String value() default "";

spring-context/src/test/java/org/springframework/scheduling/annotation/EnableAsyncTests.java

@@ -21,7 +21,6 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 import java.lang.reflect.Method;
-import java.util.Properties;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
@@ -42,13 +41,13 @@ import org.springframework.beans.factory.BeanNotOfRequiredTypeException;
 import org.springframework.beans.factory.UnsatisfiedDependencyException;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AdviceMode;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.context.annotation.Lazy;
-import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
 import org.springframework.core.Ordered;
 import org.springframework.lang.Nullable;
 import org.springframework.scheduling.concurrent.CustomizableThreadFactory;
@@ -133,26 +132,25 @@ public class EnableAsyncTests {
 	}
 
 	@Test
-	public void withAsyncBeanWithExecutorQualifiedByExpression() throws ExecutionException, InterruptedException {
-		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
-		System.getProperties().put("myExecutor", "myExecutor1");
-		PropertySourcesPlaceholderConfigurer placeholderConfigurer = new PropertySourcesPlaceholderConfigurer();
-		placeholderConfigurer.setProperties(new Properties() {{
-			put("my.app.myExecutor", "myExecutor2");
-		}});
-		placeholderConfigurer.postProcessBeanFactory(context.getBeanFactory());
+	public void withAsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder() throws Exception {
+		System.setProperty("myExecutor", "myExecutor1");
+		System.setProperty("my.app.myExecutor", "myExecutor2");
 
-		context.register(AsyncWithExecutorQualifiedByExpressionConfig.class);
-		context.refresh();
+		Class<?> configClass = AsyncWithExecutorQualifiedByExpressionConfig.class;
+		try (ConfigurableApplicationContext context = new AnnotationConfigApplicationContext(configClass)) {
+			AsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder asyncBean =
+					context.getBean(AsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder.class);
 
-		AsyncBeanWithExecutorQualifiedByExpression asyncBean = context.getBean(AsyncBeanWithExecutorQualifiedByExpression.class);
-		Future<Thread> workerThread1 = asyncBean.myWork1();
-		assertThat(workerThread1.get().getName()).doesNotStartWith("myExecutor2-").startsWith("myExecutor1-");
+			Future<Thread> workerThread1 = asyncBean.myWork1();
+			assertThat(workerThread1.get().getName()).startsWith("myExecutor1-");
 
-		Future<Thread> workerThread2 = asyncBean.myWork2();
-		assertThat(workerThread2.get().getName()).startsWith("myExecutor2-");
-
-		context.close();
+			Future<Thread> workerThread2 = asyncBean.myWork2();
+			assertThat(workerThread2.get().getName()).startsWith("myExecutor2-");
+		}
+		finally {
+			System.clearProperty("myExecutor");
+			System.clearProperty("my.app.myExecutor");
+		}
 	}
 
 	@Test
@@ -371,9 +369,9 @@ public class EnableAsyncTests {
 		}
 	}
 
-	static class AsyncBeanWithExecutorQualifiedByExpression {
+	static class AsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder {
 
-		@Async("#{systemProperties.myExecutor}")
+		@Async("#{environment['myExecutor']}")
 		public Future<Thread> myWork1() {
 			return new AsyncResult<>(Thread.currentThread());
 		}
@@ -518,8 +516,8 @@ public class EnableAsyncTests {
 	static class AsyncWithExecutorQualifiedByExpressionConfig {
 
 		@Bean
-		public AsyncBeanWithExecutorQualifiedByExpression asyncBean() {
-			return new AsyncBeanWithExecutorQualifiedByExpression();
+		public AsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder asyncBean() {
+			return new AsyncBeanWithExecutorQualifiedByExpressionOrPlaceholder();
 		}
 
 		@Bean