Check condition after calling lock method

Author: ngocnhan-tran1996

spring-rabbit-stream/src/main/java/org/springframework/rabbit/stream/producer/RabbitStreamTemplate.java

@@ -111,6 +111,7 @@ private Producer createOrGetProducer() {
 		if (this.producer == null) {
 			this.lock.lock();
 			try {
+				if (this.producer == null) {
 					ProducerBuilder builder = this.environment.producerBuilder();
 					if (this.superStreamRouting == null) {
 						builder.stream(this.streamName);
@@ -125,6 +126,7 @@ private Producer createOrGetProducer() {
 						((DefaultStreamMessageConverter) this.streamConverter).setBuilderSupplier(
 								() -> this.producer.messageBuilder());
 					}
+				}
 			}
 			finally {
 				this.lock.unlock();
@@ -332,8 +334,10 @@ public void close() {
 		if (this.producer != null) {
 			this.lock.lock();
 			try {
+				if (this.producer != null) {
 					this.producer.close();
 					this.producer = null;
+				}
 			}
 			finally {
 				this.lock.unlock();