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[英]How to implement sticky session in spring-integration tcp gateway?
[英]Spring-Integration: Tcp Server Response not sent on Exception
我將傳統的tcp服務器代碼遷移到spring-boot中,並添加了spring-intergration(基於注釋)依賴性來處理tcp套接字連接。
我的入站通道是tcpIn(),出站通道是serviceChannel(),並且我創建了一個自定義Channel [exceptionEventChannel()]來保存異常事件消息。
我有一個自定義的序列化器/反序列化方法(ByteArrayLengthPrefixSerializer()擴展了AbstractPooledBufferByteArraySerializer)和一個MessageHandler @ServiceActivator方法,用於將響應發送回tcp客戶端。
//SpringBoot 2.0.3.RELEASE, Spring Integration 5.0.6.RELEASE
package com.test.config;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.event.EventListener;
import org.springframework.integration.annotation.IntegrationComponentScan;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.annotation.Transformer;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.event.inbound.ApplicationEventListeningMessageProducer;
import org.springframework.integration.ip.IpHeaders;
import org.springframework.integration.ip.tcp.TcpReceivingChannelAdapter;
import org.springframework.integration.ip.tcp.TcpSendingMessageHandler;
import org.springframework.integration.ip.tcp.connection.*;
import org.springframework.integration.ip.tcp.serializer.TcpDeserializationExceptionEvent;
import org.springframework.integration.router.ErrorMessageExceptionTypeRouter;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandlingException;
import org.springframework.messaging.MessagingException;
import java.io.IOException;
@Configuration
@IntegrationComponentScan
public class TcpConfiguration {
@SuppressWarnings("unused")
@Value("${tcp.connection.port}")
private int tcpPort;
@Bean
TcpConnectionEventListener customerTcpListener() {
return new TcpConnectionEventListener();
}
@Bean
public MessageChannel tcpIn() {
return new DirectChannel();
}
@Bean
public MessageChannel serviceChannel() {
return new DirectChannel();
}
@ConditionalOnMissingBean(name = "errorChannel")
@Bean
public MessageChannel errorChannel() {
return new DirectChannel();
}
@Bean
public MessageChannel exceptionEventChannel() {
return new DirectChannel();
}
@Bean
public ByteArrayLengthPrefixSerializer byteArrayLengthPrefixSerializer() {
ByteArrayLengthPrefixSerializer byteArrayLengthPrefixSerializer = new ByteArrayLengthPrefixSerializer();
byteArrayLengthPrefixSerializer.setMaxMessageSize(98304); //max allowed size set to 96kb
return byteArrayLengthPrefixSerializer;
}
@Bean
public AbstractServerConnectionFactory tcpNetServerConnectionFactory() {
TcpNetServerConnectionFactory tcpServerCf = new TcpNetServerConnectionFactory(tcpPort);
tcpServerCf.setSerializer(byteArrayLengthPrefixSerializer());
tcpServerCf.setDeserializer(byteArrayLengthPrefixSerializer());
return tcpServerCf;
}
@Bean
public TcpReceivingChannelAdapter tcpReceivingChannelAdapter() {
TcpReceivingChannelAdapter adapter = new TcpReceivingChannelAdapter();
adapter.setConnectionFactory(tcpNetServerConnectionFactory());
adapter.setOutputChannel(tcpIn());
adapter.setErrorChannel(exceptionEventChannel());
return adapter;
}
@ServiceActivator(inputChannel = "exceptionEventChannel", outputChannel = "serviceChannel")
public String handle(Message<MessagingException> msg) {
//String unfilteredMessage = new String(byteMessage, StandardCharsets.US_ASCII);
System.out.println("-----------------EXCEPTION ==> " + msg);
return msg.toString();
}
@Transformer(inputChannel = "errorChannel", outputChannel = "serviceChannel")
public String transformer(String msg) {
//String unfilteredMessage = new String(byteMessage, StandardCharsets.US_ASCII);
System.out.println("-----------------ERROR ==> " + msg);
return msg.toString();
}
@ServiceActivator(inputChannel = "serviceChannel")
@Bean
public TcpSendingMessageHandler out(AbstractServerConnectionFactory cf) {
TcpSendingMessageHandler tcpSendingMessageHandler = new TcpSendingMessageHandler();
tcpSendingMessageHandler.setConnectionFactory(cf);
return tcpSendingMessageHandler;
}
@Bean
public ApplicationListener<TcpDeserializationExceptionEvent> listener() {
return new ApplicationListener<TcpDeserializationExceptionEvent>() {
@Override
public void onApplicationEvent(TcpDeserializationExceptionEvent tcpDeserializationExceptionEvent) {
exceptionEventChannel().send(MessageBuilder.withPayload(tcpDeserializationExceptionEvent.getCause())
.build());
}
};
}
}
tcpIn()中的消息被發送到一個單獨的@Component類中的@ServiceActivator方法,該類的結構如下:
@Component
public class TcpServiceActivator {
@Autowired
public TcpServiceActivator() {
}
@ServiceActivator(inputChannel = "tcpIn", outputChannel = "serviceChannel")
public String service(byte[] byteMessage) {
// Business Logic returns String Ack Response
}
運行成功方案時,我沒有任何問題。 我的Tcp TestClient得到了預期的Ack響應。
但是,當我嘗試模擬異常時,說Deserializer Exception,異常消息不會作為對Tcp Client的響應發送回去。 我可以看到我的應用程序監聽器正在獲取TcpDeserializationExceptionEvent並將消息發送到exceptionEventChannel。 @ServiceActivator方法handle(Message msg)也輸出我的異常消息。 但是它永遠不會到達MessageHandler方法out(AbstractServerConnectionFactory cf)內部的斷點(在調試模式下)。
我正在努力了解發生了什么問題。 感謝您的任何幫助。
UPDATE:我注意到在發送響應之前,套接字由於異常而關閉。 我正在嘗試解決這個問題的方法
解決方案更新(2019年3月12日):
感謝Gary的幫助,我編輯了反序列化器,以返回可以通過@Router方法跟蹤並重定向到errorChannel的消息。 然后,偵聽errorchannel的ServiceActivator將所需的錯誤消息發送到outputChannel。 此解決方案似乎有效。
我在ByteArrayLengthPrefixSerializer中使用的反序列化方法返回了Gary推薦的“特殊值”,而不是原始的InputStream消息。
public byte[] doDeserialize(InputStream inputStream, byte[] buffer) throws IOException {
boolean isValidMessage = false;
try {
int messageLength = this.readPrefix(inputStream);
if (messageLength > 0 && fillUntilMaxDeterminedSize(inputStream, buffer, messageLength)) {
return this.copyToSizedArray(buffer, messageLength);
}
return EventType.MSG_INVALID.getName().getBytes();
} catch (SoftEndOfStreamException eose) {
return EventType.MSG_INVALID.getName().getBytes();
}
}
我還創建了一些新的通道來容納我的路由器,流程如下:
成功流程tcpIn(@Router)-> serviceChannel(保存業務邏輯的@serviceActivator)-> outputChannel(將響應發送到客戶端的@serviceActivator)
異常流tcpIn(@Router)-> errorChannel(准備錯誤響應消息的@serviceActivator)-> outputChannel(將響應發送給客戶端的@serviceActivator)
我的@Router和'errorHandling'@serviceActivator-
@Router(inputChannel = "tcpIn", defaultOutputChannel = "errorChannel")
public String messageRouter(byte[] byteMessage) {
String unfilteredMessage = new String(byteMessage, StandardCharsets.US_ASCII);
System.out.println("------------------> "+unfilteredMessage);
if (Arrays.equals(EventType.MSG_INVALID.getName().getBytes(), byteMessage)) {
return "errorChannel";
}
return "serviceChannel";
}
@ServiceActivator(inputChannel = "errorChannel", outputChannel = "outputChannel")
public String errorHandler(byte[] byteMessage) {
return Message.ACK_RETRY;
}
錯誤通道用於處理在處理消息時發生的異常。 在創建消息之前,反序列化錯誤發生(解串器對消息的有效負載進行解碼)。
反序列化異常是致命的,並且如您所見,套接字已關閉。
一種選擇是在反序列化器中捕獲異常,並返回一個“特殊”值,表示發生反序列化異常,然后在主流中檢查該值。
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