Fix phase for TaskScheduler instances in tests

Related to: #8856

Many tests create their own `ThreadPoolTaskScheduler` beans.
Therefore, its default phase might affect the memory and performance.

* Use `phase = SmartLifecycle.DEFAULT_PHASE / 2` for manual
 `ThreadPoolTaskScheduler` beans
* Migrate affected tests classes to JUnit 5
* Make some other configuration adjustments for better performance

**Cherry-pick to `6.2.x`**

spring-integration-file/src/test/java/org/springframework/integration/file/FileWritingMessageHandlerTests.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.
@@ -543,6 +543,7 @@ public class FileWritingMessageHandlerTests {
 		}
 		assertThat(flushes.get()).isGreaterThanOrEqualTo(2);
 		handler.stop();
+		taskScheduler.destroy();
 	}
 
 	@Test
@@ -586,6 +587,7 @@ public class FileWritingMessageHandlerTests {
 		verify(out).write(any(byte[].class), anyInt(), anyInt());
 		assertThat(closeWhileWriting.get()).isFalse();
 		handler.stop();
+		taskScheduler.destroy();
 	}
 
 	@Test

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests-context.xml

@@ -1,14 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xmlns:int-file="http://www.springframework.org/schema/integration/file"
-	xmlns:task="http://www.springframework.org/schema/task"
-	xmlns:int="http://www.springframework.org/schema/integration"
-	xmlns:context="http://www.springframework.org/schema/context"
-	xmlns:util="http://www.springframework.org/schema/util"
-	xsi:schemaLocation="http://www.springframework.org/schema/integration https://www.springframework.org/schema/integration/spring-integration.xsd
+	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xmlns:int-file="http://www.springframework.org/schema/integration/file"
+	   xmlns:int="http://www.springframework.org/schema/integration"
+	   xmlns:context="http://www.springframework.org/schema/context"
+	   xmlns:util="http://www.springframework.org/schema/util"
+	   xsi:schemaLocation="http://www.springframework.org/schema/integration https://www.springframework.org/schema/integration/spring-integration.xsd
 		http://www.springframework.org/schema/integration/file https://www.springframework.org/schema/integration/file/spring-integration-file.xsd
-		http://www.springframework.org/schema/task https://www.springframework.org/schema/task/spring-task.xsd
+
 		http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
 		http://www.springframework.org/schema/util https://www.springframework.org/schema/util/spring-util.xsd
 		http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
@@ -16,37 +15,37 @@
 	<int:channel id="tailErrorChannel"/>
 
 	<int-file:tail-inbound-channel-adapter id="default"
-		channel="input"
-		task-executor="exec"
-		file="/tmp/baz"
-		auto-startup="true"
-		phase="123"
-		error-channel="tailErrorChannel"/>
+										   channel="input"
+										   task-executor="exec"
+										   file="/tmp/baz"
+										   auto-startup="true"
+										   phase="123"
+										   error-channel="tailErrorChannel"/>
 
 	<int-file:tail-inbound-channel-adapter id="native"
-		channel="input"
-		native-options="-F -n 6"
-		task-executor="exec"
-		task-scheduler="sched"
-		enable-status-reader="false"
-		file-delay="456"
-		file="/tmp/foo"
-		auto-startup="true"
-		delay="${empty}"
-		end="${empty}"
-		reopen="${empty}"
-		phase="123" />
+										   channel="input"
+										   native-options="-F -n 6"
+										   task-executor="exec"
+										   task-scheduler="scheduler"
+										   enable-status-reader="false"
+										   file-delay="456"
+										   file="/tmp/foo"
+										   auto-startup="true"
+										   delay="${empty}"
+										   end="${empty}"
+										   reopen="${empty}"
+										   phase="123"/>
 
 	<int-file:tail-inbound-channel-adapter id="apacheDefault"
-		channel="input"
-		native-options="${empty}"
-		task-executor="exec"
-		file="/tmp/bar"
-		delay="${foo}"
-		file-delay="10000"
-		idle-event-interval="10000"
-		auto-startup="false"
-		phase="123" />
+										   channel="input"
+										   native-options="${empty}"
+										   task-executor="exec"
+										   file="/tmp/bar"
+										   delay="${foo}"
+										   file-delay="10000"
+										   idle-event-interval="10000"
+										   auto-startup="false"
+										   phase="123"/>
 
 	<context:property-placeholder properties-ref="props"/>
 
@@ -56,20 +55,23 @@
 	</util:properties>
 
 	<int-file:tail-inbound-channel-adapter id="apacheEndReopen"
-		channel="input"
-		task-executor="exec"
-		file="/tmp/qux"
-		delay="2000"
-		file-delay="10000"
-		end="false"
-		reopen="true"
-		auto-startup="false"
-		phase="123" />
+										   channel="input"
+										   task-executor="exec"
+										   file="/tmp/qux"
+										   delay="2000"
+										   file-delay="10000"
+										   end="false"
+										   reopen="true"
+										   auto-startup="false"
+										   phase="123"/>
 
-	<int:channel id="input" />
+	<int:channel id="input"/>
 
-	<task:scheduler id="sched" />
+	<bean id="scheduler"
+		  class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler">
+		<property name="phase" value="1073741823"/>
+	</bean>
 
-	<bean class="org.springframework.integration.file.config.FileTailInboundChannelAdapterParserTests$Config" />
+	<bean class="org.springframework.integration.file.config.FileTailInboundChannelAdapterParserTests$Config"/>
 
 </beans>

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests.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.
@@ -66,7 +66,7 @@ public class FileTailInboundChannelAdapterParserTests {
 	private TaskExecutor exec;
 
 	@Autowired
-	private TaskScheduler sched;
+	private TaskScheduler scheduler;
 
 	@Autowired
 	private MessageChannel tailErrorChannel;
@@ -95,7 +95,7 @@ public class FileTailInboundChannelAdapterParserTests {
 		assertThat(normalizedName).isEqualTo("/tmp/foo");
 		assertThat(TestUtils.getPropertyValue(nativeAdapter, "command")).isEqualTo("tail -F -n 6 " + fileName);
 		assertThat(TestUtils.getPropertyValue(nativeAdapter, "taskExecutor")).isSameAs(exec);
-		assertThat(TestUtils.getPropertyValue(nativeAdapter, "taskScheduler")).isSameAs(sched);
+		assertThat(TestUtils.getPropertyValue(nativeAdapter, "taskScheduler")).isSameAs(scheduler);
 		assertThat(TestUtils.getPropertyValue(nativeAdapter, "autoStartup", Boolean.class)).isTrue();
 		assertThat(TestUtils.getPropertyValue(nativeAdapter, "enableStatusReader", Boolean.class)).isFalse();
 		assertThat(TestUtils.getPropertyValue(nativeAdapter, "phase")).isEqualTo(123);

spring-integration-file/src/test/java/org/springframework/integration/file/tail/FileTailingMessageProducerTests.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.
@@ -144,8 +144,7 @@ public class FileTailingMessageProducerTests {
 			if (event instanceof FileTailingIdleEvent) {
 				idleCountDownLatch.countDown();
 			}
-			if (event instanceof FileTailingEvent) {
-				FileTailingEvent fileTailingEvent = (FileTailingEvent) event;
+			if (event instanceof FileTailingEvent fileTailingEvent) {
 				if (fileTailingEvent.getMessage().contains("File not found")) {
 					fileExistCountDownLatch.countDown();
 				}
@@ -184,6 +183,7 @@ public class FileTailingMessageProducerTests {
 		assertThat(eventRaised).as("idle event did not emit").isTrue();
 		adapter.stop();
 		file.delete();
+		taskScheduler.destroy();
 	}
 
 	private void testGuts(FileTailingMessageProducerSupport adapter, String field) throws Exception {