Ensure Environment.shutdown() in Reactor2TcpClient

Issue: SPR-14229

spring-messaging/src/main/java/org/springframework/messaging/tcp/reactor/Reactor2TcpClient.java

@@ -84,6 +84,8 @@ public class Reactor2TcpClient<P> implements TcpOperations<P> {
 
 	private final EventLoopGroup eventLoopGroup;
 
+	private final Environment environment;
+
 	private final TcpClientFactory<Message<P>, Message<P>> tcpClientSpecFactory;
 
 	private final List<TcpClient<Message<P>, Message<P>>> tcpClients =
@@ -108,12 +110,13 @@ public class Reactor2TcpClient<P> implements TcpOperations<P> {
 		// Reactor 2.0.5 requires NioEventLoopGroup vs 2.0.6+ requires EventLoopGroup
 		final NioEventLoopGroup nioEventLoopGroup = initEventLoopGroup();
 		this.eventLoopGroup = nioEventLoopGroup;
+		this.environment = new Environment(new SynchronousDispatcherConfigReader());
 
 		this.tcpClientSpecFactory = new TcpClientFactory<Message<P>, Message<P>>() {
 			@Override
 			public TcpClientSpec<Message<P>, Message<P>> apply(TcpClientSpec<Message<P>, Message<P>> spec) {
 				return spec
-						.env(new Environment(new SynchronousDispatcherConfigReader()))
+						.env(environment)
 						.codec(codec)
 						.connect(host, port)
 						.options(createClientSocketOptions());
@@ -139,6 +142,7 @@ public class Reactor2TcpClient<P> implements TcpOperations<P> {
 		Assert.notNull(tcpClientSpecFactory, "'tcpClientClientFactory' must not be null");
 		this.tcpClientSpecFactory = tcpClientSpecFactory;
 		this.eventLoopGroup = null;
+		this.environment = null;
 	}
 
 
@@ -269,6 +273,15 @@ public class Reactor2TcpClient<P> implements TcpOperations<P> {
 			promise = eventLoopPromise;
 		}
 
+		if (this.environment != null) {
+			promise.onComplete(new Consumer<Promise<Void>>() {
+				@Override
+				public void accept(Promise<Void> voidPromise) {
+					environment.shutdown();
+				}
+			});
+		}
+
 		return new PassThroughPromiseToListenableFutureAdapter<Void>(promise);
 	}