消息顺序

来自消息代理的消息发布到 clientOutboundChannel，然后从那里写入 WebSocket 会话。由于该通道由 ThreadPoolExecutor 支持，消息在不同的线程中处理，客户端接收到的最终序列可能与发布的精确顺序不匹配。

要启用有序发布，请按如下设置 setPreservePublishOrder 标志：

Java
Kotlin
Xml

@Configuration
@EnableWebSocketMessageBroker
public class PublishOrderWebSocketConfiguration implements WebSocketMessageBrokerConfigurer {

	@Override
	public void configureMessageBroker(MessageBrokerRegistry registry) {
		// ...
		registry.setPreservePublishOrder(true);
	}

}

@Configuration
@EnableWebSocketMessageBroker
class PublishOrderWebSocketConfiguration : WebSocketMessageBrokerConfigurer {

	override fun configureMessageBroker(registry: MessageBrokerRegistry) {
		// ...
		registry.setPreservePublishOrder(true)
	}
}

<beans xmlns="http://www.springframework.org/schema/beans"
	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	   xmlns:websocket="http://www.springframework.org/schema/websocket"
	   xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		https://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/websocket
		https://www.springframework.org/schema/websocket/spring-websocket.xsd">

	<websocket:message-broker preserve-publish-order="true">
		<!-- ... -->
	</websocket:message-broker>

</beans>

当设置此标志时，同一客户端会话中的消息将一次性发布到 clientOutboundChannel，从而保证了发布顺序。请注意，这会带来一些性能开销，因此仅在需要时才应启用它。

同样，来自客户端的消息也会发送到 clientInboundChannel，然后根据其目的地前缀进行处理。由于该通道由 ThreadPoolExecutor 支持，消息在不同的线程中处理，因此处理的最终序列可能与接收到的精确顺序不匹配。

要启用有序接收，请按如下设置 setPreserveReceiveOrder 标志：

Java
Kotlin

@Configuration
@EnableWebSocketMessageBroker
public class ReceiveOrderWebSocketConfiguration implements WebSocketMessageBrokerConfigurer {

	@Override
	public void registerStompEndpoints(StompEndpointRegistry registry) {
		registry.setPreserveReceiveOrder(true);
	}
}

@Configuration
@EnableWebSocketMessageBroker
class ReceiveOrderWebSocketConfiguration : WebSocketMessageBrokerConfigurer {

	override fun registerStompEndpoints(registry: StompEndpointRegistry) {
		registry.setPreserveReceiveOrder(true)
	}
}