Default time zone resolution from scheduler-wide Clock

Closes gh-31948

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -102,9 +102,9 @@ public @interface Scheduled {
 
 	/**
 	 * A time zone for which the cron expression will be resolved. By default, this
-	 * attribute is the empty String (i.e. the server's local time zone will be used).
+	 * attribute is the empty String (i.e. the scheduler's time zone will be used).
 	 * @return a zone id accepted by {@link java.util.TimeZone#getTimeZone(String)},
-	 * or an empty String to indicate the server's default time zone
+	 * or an empty String to indicate the scheduler's default time zone
 	 * @since 4.0
 	 * @see org.springframework.scheduling.support.CronTrigger#CronTrigger(String, java.util.TimeZone)
 	 * @see java.util.TimeZone

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -26,7 +26,6 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.TimeZone;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -430,14 +429,14 @@ public class ScheduledAnnotationBeanPostProcessor
 					Assert.isTrue(initialDelay.isNegative(), "'initialDelay' not supported for cron triggers");
 					processedSchedule = true;
 					if (!Scheduled.CRON_DISABLED.equals(cron)) {
-						TimeZone timeZone;
+						CronTrigger trigger;
 						if (StringUtils.hasText(zone)) {
-							timeZone = StringUtils.parseTimeZoneString(zone);
+							trigger = new CronTrigger(cron, StringUtils.parseTimeZoneString(zone));
 						}
 						else {
-							timeZone = TimeZone.getDefault();
+							trigger = new CronTrigger(cron);
 						}
-						tasks.add(this.registrar.scheduleCronTask(new CronTask(runnable, new CronTrigger(cron, timeZone))));
+						tasks.add(this.registrar.scheduleCronTask(new CronTask(runnable, trigger)));
 					}
 				}
 			}

spring-context/src/main/java/org/springframework/scheduling/support/CronExpression.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -168,7 +168,7 @@ public final class CronExpression {
 	 * the cron format
 	 */
 	public static CronExpression parse(String expression) {
-		Assert.hasLength(expression, "Expression string must not be empty");
+		Assert.hasLength(expression, "Expression must not be empty");
 
 		expression = resolveMacros(expression);
 

spring-context/src/main/java/org/springframework/scheduling/support/CronTrigger.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -39,6 +39,7 @@ public class CronTrigger implements Trigger {
 
 	private final CronExpression expression;
 
+	@Nullable
 	private final ZoneId zoneId;
 
 
@@ -48,7 +49,8 @@ public class CronTrigger implements Trigger {
 	 * expression conventions
 	 */
 	public CronTrigger(String expression) {
-		this(expression, ZoneId.systemDefault());
+		this.expression = CronExpression.parse(expression);
+		this.zoneId = null;
 	}
 
 	/**
@@ -58,7 +60,9 @@ public class CronTrigger implements Trigger {
 	 * @param timeZone a time zone in which the trigger times will be generated
 	 */
 	public CronTrigger(String expression, TimeZone timeZone) {
-		this(expression, timeZone.toZoneId());
+		this.expression = CronExpression.parse(expression);
+		Assert.notNull(timeZone, "TimeZone must not be null");
+		this.zoneId = timeZone.toZoneId();
 	}
 
 	/**
@@ -70,10 +74,8 @@ public class CronTrigger implements Trigger {
 	 * @see CronExpression#parse(String)
 	 */
 	public CronTrigger(String expression, ZoneId zoneId) {
-		Assert.hasLength(expression, "Expression must not be empty");
-		Assert.notNull(zoneId, "ZoneId must not be null");
-
 		this.expression = CronExpression.parse(expression);
+		Assert.notNull(zoneId, "ZoneId must not be null");
 		this.zoneId = zoneId;
 	}
 
@@ -94,22 +96,23 @@ public class CronTrigger implements Trigger {
 	 */
 	@Override
 	public Instant nextExecution(TriggerContext triggerContext) {
-		Instant instant = triggerContext.lastCompletion();
-		if (instant != null) {
+		Instant timestamp = triggerContext.lastCompletion();
+		if (timestamp != null) {
 			Instant scheduled = triggerContext.lastScheduledExecution();
-			if (scheduled != null && instant.isBefore(scheduled)) {
+			if (scheduled != null && timestamp.isBefore(scheduled)) {
 				// Previous task apparently executed too early...
 				// Let's simply use the last calculated execution time then,
 				// in order to prevent accidental re-fires in the same second.
-				instant = scheduled;
+				timestamp = scheduled;
 			}
 		}
 		else {
-			instant = triggerContext.getClock().instant();
+			timestamp = triggerContext.getClock().instant();
 		}
-		ZonedDateTime dateTime = ZonedDateTime.ofInstant(instant, this.zoneId);
-		ZonedDateTime next = this.expression.next(dateTime);
-		return (next != null ? next.toInstant() : null);
+		ZoneId zone = (this.zoneId != null ? this.zoneId : triggerContext.getClock().getZone());
+		ZonedDateTime zonedTimestamp = ZonedDateTime.ofInstant(timestamp, zone);
+		ZonedDateTime nextTimestamp = this.expression.next(zonedTimestamp);
+		return (nextTimestamp != null ? nextTimestamp.toInstant() : null);
 	}
 
 

spring-context/src/test/java/org/springframework/scheduling/support/CronTriggerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -848,6 +848,7 @@ class CronTriggerTests {
 		assertThat(nextExecutionTime).isEqualTo(this.calendar.getTime());
 	}
 
+
 	private static void roundup(Calendar calendar) {
 		calendar.add(Calendar.SECOND, 1);
 		calendar.set(Calendar.MILLISECOND, 0);
@@ -861,9 +862,7 @@ class CronTriggerTests {
 	}
 
 	private static TriggerContext getTriggerContext(Date lastCompletionTime) {
-		SimpleTriggerContext context = new SimpleTriggerContext();
-		context.update(null, null, lastCompletionTime);
-		return context;
+		return new SimpleTriggerContext(null, null, lastCompletionTime);
 	}