Use default phase 0 for WebSocket messaging

Closes gh-27519

Author: rstoyanchev

spring-messaging/src/main/java/org/springframework/messaging/simp/annotation/support/SimpAnnotationMethodMessageHandler.java

@@ -276,7 +276,8 @@ public MessageHeaderInitializer getHeaderInitializer() {
 
 	/**
 	 * Set the phase that this handler should run in.
-	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}.
+	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}, but with
+	 * {@code @EnableWebSocketMessageBroker} configuration it is set to 0.
 	 * @since 6.1.4
 	 */
 	public void setPhase(int phase) {

spring-messaging/src/main/java/org/springframework/messaging/simp/broker/AbstractBrokerMessageHandler.java

@@ -202,7 +202,8 @@ public boolean isAutoStartup() {
 
 	/**
 	 * Set the phase that this handler should run in.
-	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}.
+	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}, but with
+	 * {@code @EnableWebSocketMessageBroker} configuration it is set to 0.
 	 * @since 6.1.4
 	 */
 	public void setPhase(int phase) {

spring-messaging/src/main/java/org/springframework/messaging/simp/config/AbstractMessageBrokerConfiguration.java

@@ -28,7 +28,6 @@
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
-import org.springframework.context.SmartLifecycle;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.event.SmartApplicationListener;
 import org.springframework.lang.Nullable;
@@ -197,7 +196,7 @@ protected final int getPhase() {
 	}
 
 	protected int initPhase() {
-		return SmartLifecycle.DEFAULT_PHASE;
+		return 0;
 	}
 
 	/**

spring-messaging/src/main/java/org/springframework/messaging/simp/user/UserDestinationMessageHandler.java

@@ -159,7 +159,8 @@ public MessageHeaderInitializer getHeaderInitializer() {
 
 	/**
 	 * Set the phase that this handler should run in.
-	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}.
+	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}, but with
+	 * {@code @EnableWebSocketMessageBroker} configuration it is set to 0.
 	 * @since 6.1.4
 	 */
 	public void setPhase(int phase) {

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/WebSocketMessageBrokerConfigurer.java

@@ -117,11 +117,9 @@ default void configureMessageBroker(MessageBrokerRegistry registry) {
 	 * handling beans of type {@link SmartLifecycle} should run in.
 	 * <p>The default implementation returns {@code null} which allows other
 	 * configurers to decide. As soon as any configurer returns a value, that
-	 * value is used. If no configurer returns a value, then by default
-	 * {@link SmartLifecycle#DEFAULT_PHASE} is used.
+	 * value is used. If no configurer returns a value, then 0 is used.
 	 * <p>It is recommended to use a phase value such as 0 in order to ensure that
-	 * components start before the web server in Spring Boot application. In 6.2.0,
-	 * the default used will change to 0.
+	 * components start before the web server in Spring Boot application.
 	 * @since 6.1.4
 	 * @see SmartLifecycle
 	 */

spring-websocket/src/main/java/org/springframework/web/socket/messaging/SubProtocolWebSocketHandler.java

@@ -254,7 +254,8 @@ public int getTimeToFirstMessage() {
 
 	/**
 	 * Set the phase that this handler should run in.
-	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}.
+	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}, but with
+	 * {@code @EnableWebSocketMessageBroker} configuration it is set to 0.
 	 * @since 6.1.4
 	 */
 	public void setPhase(int phase) {

spring-websocket/src/main/java/org/springframework/web/socket/server/support/WebSocketHandlerMapping.java

@@ -62,7 +62,8 @@ public void setWebSocketUpgradeMatch(boolean match) {
 
 	/**
 	 * Set the phase that this handler should run in.
-	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}.
+	 * <p>By default, this is {@link SmartLifecycle#DEFAULT_PHASE}, but with
+	 * {@code @EnableWebSocketMessageBroker} configuration it is set to 0.
 	 * @since 6.1.4
 	 */
 	public void setPhase(int phase) {

spring-websocket/src/test/java/org/springframework/web/socket/config/annotation/WebSocketMessageBrokerConfigurationSupportTests.java

@@ -212,10 +212,18 @@ void webSocketMessageBrokerStats() {
 	}
 
 	@Test
-	void lifecyclePhase() {
+	void lifecyclePhaseDefault() {
+		ApplicationContext context = createContext(TestChannelConfig.class, TestConfigurer.class);
+		assertPhase(context, 0);
+	}
+
+	@Test
+	void lifecyclePhaseExplicitlySet() {
 		ApplicationContext context = createContext(LifecyclePhaseConfig.class);
+		assertPhase(context, 99);
+	}
 
-		int phase = 99;
+	private static void assertPhase(ApplicationContext context, int phase) {
 		Consumer<String> executorTester = beanName ->
 				assertThat(context.getBean(beanName, ThreadPoolTaskExecutor.class).getPhase()).isEqualTo(phase);