From ff1e5a87b3ef452b480e775d3af7eda2d8bea0f8 Mon Sep 17 00:00:00 2001
From: Sam Brannen <104798+sbrannen@users.noreply.github.com>
Date: Sat, 12 Jul 2025 16:22:35 +0200
Subject: [PATCH] Introduce ContextRestartedEvent as a subtype of
 ContextStartedEvent

Prior to this commit, there was no way to differentiate between an
ApplicationContext "start" and "restart" in terms of events. This was
due to the fact that a ContextStartedEvent was fired for both
AbstractApplicationContext.start() and
AbstractApplicationContext.restart().

To assist developers who may wish to differentiate between "start" and
"restart" events, this commit introduces a new ContextRestartedEvent as
a subtype of ContextStartedEvent. In addition,
AbstractApplicationContext.restart() now publishes a
ContextRestartedEvent instead of a ContextStartedEvent.

By making ContextRestartedEvent a subtype of ContextStartedEvent,
applications can still expect ContextStoppedEvent/ContextStartedEvent
event pairs for consistent lifecycle semantics, and they can optionally
check if the ContextStartedEvent is a ContextRestartedEvent.
Alternatively, applications can explicitly react to a
ContextRestartedEvent.

See gh-35168
See gh-35171
Closes gh-35194
---
 .../context/event/ContextRestartedEvent.java  | 44 +++++++++++++++++++
 .../context/event/ContextStartedEvent.java    |  1 +
 .../context/event/ContextStoppedEvent.java    |  1 +
 .../support/AbstractApplicationContext.java   |  3 +-
 4 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 spring-context/src/main/java/org/springframework/context/event/ContextRestartedEvent.java

diff --git a/spring-context/src/main/java/org/springframework/context/event/ContextRestartedEvent.java b/spring-context/src/main/java/org/springframework/context/event/ContextRestartedEvent.java
new file mode 100644
index 00000000000..e8165be8d08
--- /dev/null
+++ b/spring-context/src/main/java/org/springframework/context/event/ContextRestartedEvent.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2002-present 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.context.event;
+
+import org.springframework.context.ApplicationContext;
+
+/**
+ * Event raised when an {@code ApplicationContext} gets restarted.
+ *
+ * <p>Note that {@code ContextRestartedEvent} is a specialization of
+ * {@link ContextStartedEvent}.
+ *
+ * @author Sam Brannen
+ * @since 7.0
+ * @see ContextStartedEvent
+ * @see ContextStoppedEvent
+ */
+@SuppressWarnings("serial")
+public class ContextRestartedEvent extends ContextStartedEvent {
+
+	/**
+	 * Create a new {@code ContextRestartedEvent}.
+	 * @param source the {@code ApplicationContext} that has been restarted
+	 * (must not be {@code null})
+	 */
+	public ContextRestartedEvent(ApplicationContext source) {
+		super(source);
+	}
+
+}
diff --git a/spring-context/src/main/java/org/springframework/context/event/ContextStartedEvent.java b/spring-context/src/main/java/org/springframework/context/event/ContextStartedEvent.java
index b67513815ac..d304b07c97a 100644
--- a/spring-context/src/main/java/org/springframework/context/event/ContextStartedEvent.java
+++ b/spring-context/src/main/java/org/springframework/context/event/ContextStartedEvent.java
@@ -24,6 +24,7 @@ import org.springframework.context.ApplicationContext;
  * @author Mark Fisher
  * @author Juergen Hoeller
  * @since 2.5
+ * @see ContextRestartedEvent
  * @see ContextStoppedEvent
  */
 @SuppressWarnings("serial")
diff --git a/spring-context/src/main/java/org/springframework/context/event/ContextStoppedEvent.java b/spring-context/src/main/java/org/springframework/context/event/ContextStoppedEvent.java
index 76d241d2bb4..0a18921556c 100644
--- a/spring-context/src/main/java/org/springframework/context/event/ContextStoppedEvent.java
+++ b/spring-context/src/main/java/org/springframework/context/event/ContextStoppedEvent.java
@@ -25,6 +25,7 @@ import org.springframework.context.ApplicationContext;
  * @author Juergen Hoeller
  * @since 2.5
  * @see ContextStartedEvent
+ * @see ContextRestartedEvent
  */
 @SuppressWarnings("serial")
 public class ContextStoppedEvent extends ApplicationContextEvent {
diff --git a/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java b/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java
index 2daed0cee3e..05d8f8ddd3e 100644
--- a/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java
+++ b/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java
@@ -67,6 +67,7 @@ import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.event.ApplicationEventMulticaster;
 import org.springframework.context.event.ContextClosedEvent;
 import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.ContextRestartedEvent;
 import org.springframework.context.event.ContextStartedEvent;
 import org.springframework.context.event.ContextStoppedEvent;
 import org.springframework.context.event.SimpleApplicationEventMulticaster;
@@ -1551,7 +1552,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	@Override
 	public void restart() {
 		getLifecycleProcessor().onRestart();
-		publishEvent(new ContextStartedEvent(this));
+		publishEvent(new ContextRestartedEvent(this));
 	}
 
 	@Override