Merge branch '3.5.x'

Closes gh-48487

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/health/RabbitHealthIndicator.java

@@ -52,7 +52,7 @@ public class RabbitHealthIndicator extends AbstractHealthIndicator {
 
 	private @Nullable String getVersion() {
 		return this.rabbitTemplate.execute((channel) -> {
-			Object version = channel.getConnection().getServerProperties().get("version");
+			Object version = channel.getConnection().getServerProperties().getOrDefault("version", "unknown");
 			Assert.state(version != null, "'version' must not be null");
 			return version.toString();
 		});

module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/health/RabbitHealthIndicatorTests.java

@@ -70,6 +70,17 @@ class RabbitHealthIndicatorTests {
 		assertThat(health.getDetails()).containsEntry("version", "123");
 	}
 
+	@Test
+	void healthWhenVersionIsMissingShouldReturnUpWithUnknownVersion() {
+		givenTemplateExecutionWillInvokeCallback();
+		Connection connection = mock(Connection.class);
+		given(this.channel.getConnection()).willReturn(connection);
+		given(connection.getServerProperties()).willReturn(Collections.emptyMap());
+		Health health = new RabbitHealthIndicator(this.rabbitTemplate).health();
+		assertThat(health.getStatus()).isEqualTo(Status.UP);
+		assertThat(health.getDetails()).containsEntry("version", "unknown");
+	}
+
 	@Test
 	void healthWhenConnectionFailsShouldReturnDown() {
 		givenTemplateExecutionWillInvokeCallback();