Spring integration Java DSL http outbound - spring-integration

Question

How to resend same or modified message from outbound http call in case of specific client error responses like 400, 413 etc
#Bean
private IntegrationFlow myChannel() {
IntegrationFlowBuilder builder =
IntegrationFlows.from(queue)
.handle(//http post method config)
...
.expectedResponseType(String.class))
.channel(MessageChannels.publishSubscribe(channel2));
return builder.get();
}
#Bean
private IntegrationFlow defaultErrorChannel() {
}
EDIT: Added end point to handle method
#Bean
private IntegrationFlow myChannel() {
IntegrationFlowBuilder builder =
IntegrationFlows.from(queue)
.handle(//http post method config)
...
.expectedResponseType(String.class),
e -> e.advice(myRetryAdvice()))
.channel(MessageChannels.publishSubscribe(channel2));
return builder.get();
}
#Bean
public Advice myRetryAdvice(){
... // set custom retry policy
}
Custom Retry policy:
class InternalServerExceptionClassifierRetryPolicy extends
ExceptionClassifierRetryPolicy {
public InternalServerExceptionClassifierRetryPolicy() {
final SimpleRetryPolicy simpleRetryPolicy =
new SimpleRetryPolicy();
simpleRetryPolicy.setMaxAttempts(2);
this.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
#Override
public RetryPolicy classify(Throwable classifiable) {
if (classifiable instanceof HttpServerErrorException) {
// For specifically 500 and 504
if (((HttpServerErrorException) classifiable).getStatusCode() == HttpStatus.INTERNAL_SERVER_ERROR
|| ((HttpServerErrorException) classifiable)
.getStatusCode() == HttpStatus.GATEWAY_TIMEOUT) {
return simpleRetryPolicy;
}
return new NeverRetryPolicy();
}
return new NeverRetryPolicy();
}
});
}}
EDIT 2: Override open() to modify the original message
RequestHandlerRetryAdvice retryAdvice = new
RequestHandlerRetryAdvice(){
#Override
public<T, E extends Throwable> boolean open(RetryContext
retryContext, RetryCallback<T,E> callback){
Message<String> originalMsg =
(Message) retryContext.getAttribute(ErrorMessageUtils.FAILED_MESSAGE_CONTEXT);
Message<String> updatedMsg = //some updated message
retryContext.setAttribute(ErrorMessageUtils.FAILED_MESSAGE_CONTEXT,up datedMsg);
return super.open(retryContext, callback);
}

Answer 1

See a RequestHandlerRetryAdvice: https://docs.spring.io/spring-integration/reference/html/messaging-endpoints.html#message-handler-advice-chain. So, you configure some RetryPolicy to check those HttpClientErrorException for retry and the framework will re-send for you.
Java DSL allows us to configure it via second handle() argument - endpoint configurer: .handle(..., e -> e.advice(myRetryAdvice)): https://docs.spring.io/spring-integration/reference/html/dsl.html#java-dsl-endpoints