Add Java configuration for control-bus sample

Introduce Java-based Spring Integration configuration as an
alternative to the existing XML configuration. The new
ControlBusConfiguration class uses `@Configuration` and Integration
DSL to define the control bus flow and inbound adapter.

The application.properties file sets `java-config` as the default
profile, allowing users to run the sample with Java configuration
out of the box. The XML configuration remains available by
explicitly activating the `xml-config` profile.

Author: cppwfs

basic/control-bus/README.md

@@ -1,11 +1,44 @@
 Control Bus Sample
 ==================
 
-This example demonstrates the functionality of the Control Bus component available with Spring Integration. The Control Bus uses SpEL to send a Control Message to start/stop an inbound adapter. To run the Control Bus sample simply execute **ControlBusDemoTest** in the **org.springframework.integration.samples.controlbus** package.
+This example demonstrates the functionality of the Control Bus component available with Spring Integration. The Control Bus uses SpEL to send a Control Message to start/stop an inbound adapter.
 
-You will see output similar to this:
+This sample supports both **XML-based** and **Java-based** Spring Integration configurations. You can select which configuration to use by setting the active Spring profile.
+
+## Configuration Options
+
+This sample supports two configuration modes:
+
+* **Java Configuration** (`java-config` profile) - Uses Java `@Configuration` classes from the `config` package. This is the **default** mode.
+* **XML Configuration** (`xml-config` profile) - Uses XML configuration files from `META-INF/spring/integration/`
+
+### Profile Selection
+
+Only one configuration profile should be active at a time. The `java-config` and `xml-config` profiles are mutually exclusive.
+
+* If no profile is explicitly provided, `java-config` is used by default (as configured in `application.properties`).
+* To use XML configuration, explicitly activate the `xml-config` profile at runtime.
+
+## Running the Sample
 
-	INFO : org.springframework.integration.samples.jmx.ControlBusDemo - Received before adapter started: null
-	INFO : org.springframework.integration.samples.jmx.ControlBusDemo - Received before adapter started: [Payload=Hello][Headers={timestamp=1294950897714, id=240e72fb-93b0-4d38-8fe8-b701cf7e9a5d}]
-	INFO : org.springframework.integration.samples.jmx.ControlBusDemo - Received after adapter stopped: null
+### Using Java Configuration (Default)
+
+The sample uses Java configuration by default. Execute **ControlBusDemoTest** in the **org.springframework.integration.samples.controlbus** package. The test method `demoControlBusWithJavaConfig()` demonstrates the Java configuration mode.
+
+In this mode, the application context is defined using Spring Integration Java configuration classes instead of XML. The configuration classes are located in the `org.springframework.integration.samples.controlbus.config` package.
+
+### Using XML Configuration
+
+To run the sample with XML configuration, activate the `xml-config` profile. The test method `demoControlBusWithXmlConfig()` demonstrates this mode.
+
+This mode uses the legacy XML-based wiring from `ControlBusDemo-context.xml`. The XML namespace is only active when the `xml-config` profile is enabled.
+
+## Expected Output
+
+You will see output similar to this:
 
+```
+INFO : org.springframework.integration.samples.controlbus.ControlBusDemoTest - Received before adapter started: null
+INFO : org.springframework.integration.samples.controlbus.ControlBusDemoTest - Received before adapter started: [Payload=Hello][Headers={timestamp=1294950897714, id=240e72fb-93b0-4d38-8fe8-b701cf7e9a5d}]
+INFO : org.springframework.integration.samples.controlbus.ControlBusDemoTest - Received after adapter stopped: null
+```

basic/control-bus/src/main/java/org/springframework/integration/samples/controlbus/config/ControlBusConfiguration.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2025-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.integration.samples.controlbus.config;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.integration.channel.DirectChannel;
+import org.springframework.integration.channel.QueueChannel;
+import org.springframework.integration.config.EnableIntegration;
+import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.dsl.Pollers;
+import org.springframework.messaging.MessageChannel;
+
+/**
+ * Java-based Spring Integration configuration for the Control Bus sample.
+ * <p>
+ * This configuration demonstrates the Control Bus component functionality,
+ * which uses SpEL expressions to control Spring Integration endpoints
+ * (e.g., start/stop an inbound adapter).
+ * <p>
+ * Activate this configuration using the "java-config" profile.
+ * <p>
+ * This configuration is functionally equivalent to {@code ControlBusDemo-context.xml}
+ * and defines:
+ * <ul>
+ *   <li>A control channel for sending control messages</li>
+ *   <li>An output channel (queue-based) for the inbound adapter</li>
+ *   <li>A control bus endpoint that processes control messages</li>
+ *   <li>An inbound channel adapter that generates "Hello" messages at a fixed rate</li>
+ * </ul>
+ *
+ * @author Glenn Renfro
+ */
+@Configuration
+@EnableIntegration
+@Profile("java-config")
+public class ControlBusConfiguration {
+
+	/**
+	 * Create a direct channel for sending control messages to the control bus.
+	 * <p>
+	 * This channel is used to send SpEL expressions that control Spring Integration
+	 * endpoints (e.g., {@code @inboundAdapter.start()} or {@code @inboundAdapter.stop()}).
+	 *
+	 * @return a DirectChannel for control messages
+	 */
+	@Bean
+	public MessageChannel controlChannel() {
+		return new DirectChannel();
+	}
+
+	/**
+	 * Create a queue-based channel for receiving messages from the inbound adapter.
+	 * <p>
+	 * This channel uses a queue to allow asynchronous message consumption.
+	 *
+	 * @return a QueueChannel for adapter output
+	 */
+	@Bean
+	public MessageChannel adapterOutputChannel() {
+		return new QueueChannel();
+	}
+
+	/**
+	 * Create an integration flow that connects the control channel to the control bus.
+	 * <p>
+	 * Messages sent to the control channel are processed by the control bus,
+	 * which evaluates SpEL expressions to control Spring Integration endpoints.
+	 *
+	 * @param controlChannel input channel for control commands
+	 * @return an IntegrationFlow connecting controlChannel to controlBus
+	 */
+	@Bean
+	public IntegrationFlow controlBusFlow(@Qualifier("controlChannel") MessageChannel controlChannel) {
+		return IntegrationFlow.from(controlChannel)
+				.controlBus()
+				.get();
+	}
+
+	/**
+	 * Create an inbound channel adapter that generates messages.
+	 * <p>
+	 * The adapter:
+	 * <ul>
+	 *   <li>Generates the string "Hello" as the payload</li>
+	 *   <li>Sends messages to the adapterOutputChannel</li>
+	 *   <li>Starts with auto-startup disabled (must be started via control bus)</li>
+	 *   <li>Polls at a fixed rate of 1000ms</li>
+	 * </ul>
+	 *
+	 * @return an IntegrationFlow representing the inbound adapter
+	 */
+	@Bean
+	public IntegrationFlow inboundAdapter() {
+		return IntegrationFlow.fromSupplier(() -> "Hello",
+						c -> c.id("inboundAdapter")
+								.autoStartup(false)
+								.poller(Pollers.fixedRate(1000)))
+				.channel(adapterOutputChannel())
+				.get();
+	}
+
+}
+

basic/control-bus/src/main/resources/META-INF/spring/integration/ControlBusDemo-context.xml

@@ -7,14 +7,14 @@
 
 	<int:channel id="controlChannel"/>
 
-	<int:channel id="adapterOutputChanel">
+	<int:channel id="adapterOutputChannel">
 		<int:queue/>
 	</int:channel>
 
 	<int:control-bus input-channel="controlChannel"/>
 
 	<int:inbound-channel-adapter id="inboundAdapter"
-							     channel="adapterOutputChanel" 
+							     channel="adapterOutputChannel"
 								 expression="'Hello'"
 								 auto-startup="false">
 		<int:poller fixed-rate="1000"/>

basic/control-bus/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+spring.profiles.active=java-config
+

basic/control-bus/src/test/java/org/springframework/integration/samples/controlbus/ControlBusDemoTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2017-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.
@@ -20,31 +20,49 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.PollableChannel;
 import org.springframework.messaging.support.GenericMessage;
 
 /**
  * @author Oleg Zhurakousky
  * @author Gary Russell
+ * @author Glenn Renfro
  *
  */
 public class ControlBusDemoTest {
 
 	private static Log logger = LogFactory.getLog(ControlBusDemoTest.class);
 
 	@Test
-	public void demoControlBus(){
+	public void demoControlBusWithJavaConfig() {
+		AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext();
+		ac.setEnvironment(new StandardEnvironment());
+		ac.getEnvironment().setActiveProfiles("java-config");
+		ac.scan("org.springframework.integration.samples.controlbus.config");
+		ac.refresh();
+		runControlBusDemo(ac);
+		ac.close();
+	}
+
+	@Test
+	public void demoControlBusWithXmlConfig() {
 		ConfigurableApplicationContext ac = new ClassPathXmlApplicationContext(
 				"/META-INF/spring/integration/ControlBusDemo-context.xml");
+		runControlBusDemo(ac);
+		ac.close();
+	}
+
+	private void runControlBusDemo(ConfigurableApplicationContext ac) {
 		MessageChannel controlChannel = ac.getBean("controlChannel", MessageChannel.class);
-		PollableChannel adapterOutputChanel = ac.getBean("adapterOutputChanel", PollableChannel.class);
-		logger.info("Received before adapter started: " + adapterOutputChanel.receive(1000));
+		PollableChannel adapterOutputChannel = ac.getBean("adapterOutputChannel", PollableChannel.class);
+		logger.info("Received before adapter started: " + adapterOutputChannel.receive(1000));
 		controlChannel.send(new GenericMessage<String>("@inboundAdapter.start()"));
-		logger.info("Received before adapter started: " + adapterOutputChanel.receive(1000));
+		logger.info("Received before adapter started: " + adapterOutputChannel.receive(1000));
 		controlChannel.send(new GenericMessage<String>("@inboundAdapter.stop()"));
-		logger.info("Received after adapter stopped: " + adapterOutputChanel.receive(1000));
-		ac.close();
+		logger.info("Received after adapter stopped: " + adapterOutputChannel.receive(1000));
 	}
 }