WIP: Reinstate support for auto-configuring an embedded ActiveMQ broker

Author: mattrpav

spring-boot-project/spring-boot-actuator-autoconfigure/build.gradle

@@ -78,6 +78,7 @@ dependencies {
 	optional("jakarta.servlet:jakarta.servlet-api")
 	optional("javax.cache:cache-api")
 	optional("org.apache.activemq:activemq-client")
+	optional("org.apache.activemq:activemq-broker")
 	optional("org.apache.commons:commons-dbcp2") {
 		exclude group: "commons-logging", module: "commons-logging"
 	}

spring-boot-project/spring-boot-autoconfigure/build.gradle

@@ -77,6 +77,7 @@ dependencies {
 	optional("javax.cache:cache-api")
 	optional("javax.money:money-api")
 	optional("org.apache.activemq:activemq-client")
+	optional("org.apache.activemq:activemq-broker")
 	optional("org.apache.activemq:artemis-jakarta-client") {
 		exclude group: "commons-logging", module: "commons-logging"
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jms/activemq/ActiveMQProperties.java

@@ -37,13 +37,21 @@
 @ConfigurationProperties(prefix = "spring.activemq")
 public class ActiveMQProperties {
 
+	private static final String DEFAULT_EMBEDDED_BROKER_URL = "vm://localhost?broker.persistent=false";
+
 	private static final String DEFAULT_NETWORK_BROKER_URL = "tcp://localhost:61616";
 
 	/**
 	 * URL of the ActiveMQ broker. Auto-generated by default.
 	 */
 	private String brokerUrl;
 
+	/**
+	 * Whether the default broker URL should be in memory. Ignored if an explicit broker
+	 * has been specified.
+	 */
+	private boolean inMemory = true;
+
 	/**
 	 * Login user of the broker.
 	 */
@@ -83,6 +91,14 @@ public void setBrokerUrl(String brokerUrl) {
 		this.brokerUrl = brokerUrl;
 	}
 
+	public boolean isInMemory() {
+		return this.inMemory;
+	}
+
+	public void setInMemory(boolean inMemory) {
+		this.inMemory = inMemory;
+	}
+
 	public String getUser() {
 		return this.user;
 	}
@@ -132,8 +148,11 @@ public Packages getPackages() {
 	}
 
 	String determineBrokerUrl() {
-		if (this.brokerUrl != null) {
-			return this.brokerUrl;
+		if (this.getBrokerUrl() != null) {
+			return this.getBrokerUrl();
+		}
+		if (this.isInMemory()) {
+			return DEFAULT_EMBEDDED_BROKER_URL;
 		}
 		return DEFAULT_NETWORK_BROKER_URL;
 	}

spring-boot-project/spring-boot-starters/spring-boot-starter-activemq/build.gradle

@@ -8,4 +8,5 @@ dependencies {
 	api(project(":spring-boot-project:spring-boot-starters:spring-boot-starter"))
 	api("org.springframework:spring-jms")
 	api("org.apache.activemq:activemq-client")
+	api("org.apache.activemq:activemq-broker")
 }