Usage of exceptionExpression in Spring Retry - spring

Question

According to documentation, I can use something like this in exceptionExpression: #Retryable(exceptionExpression="message.contains('this can be retried')")
But I want to get response body and check message inside it (from RestClientResponseException), something similar to this: exceptionExpression = "getResponseBodyAsString().contains('important message')"
I tried like that but it doesn't work. So, is it possible to do something similar and check info from responseBody?
Edit: Adding whole #Retryable annotation parameters with Gary Russell's suggestion:
#Retryable(value = HttpClientErrorException.class, exceptionExpression = "#{#root instanceof T(org.springframework.web.client.HttpClientErrorException) AND responseBodyAsString.contains('important message')}")
I'm using actual RestClientResponseException subclass that I'm catching but is still not triggering retry.

Answer 1

With the current release, the expression incorrectly requires static template markers; they will not be needed in 1.3.
#Retryable(exceptionExpression = "#{responseBodyAsString.contains('foo')}")
However, you can't use this expression if there are include or exclude properties so the expression should check the type:
#Retryable(exceptionExpression =
"#{#root instanceof T(org.springframework.web.client.RestClientResponseException) "
+ "AND responseBodyAsString.contains('foo')}")
EDIT
#SpringBootApplication
#EnableRetry
public class So61488237Application {
public static void main(String[] args) {
SpringApplication.run(So61488237Application.class, args).close();
}
#Bean
public ApplicationRunner runner(Foo foo) {
return args -> {
try {
foo.test(1, "foo.");
}
catch (Exception e) {
}
};
}
}
#Component
class Foo {
#Retryable(exceptionExpression =
"#{#root instanceof T(org.springframework.web.client.RestClientException) "
+ "AND responseBodyAsString.contains('foo')}")
public void test(int val, String str) {
System.out.println(val + ":" + str);
throw new RestClientResponseException("foo", 500, "bar", new HttpHeaders(), "foo".getBytes(),
StandardCharsets.UTF_8);
}
}
1:foo.
1:foo.
1:foo.

Answer 2

I've implemented the following approach, which in my opinion is much more convenient.
#Retryable(value = WebClientException.class,
exceptionExpression = RetryCheckerService.EXPRESSION,
maxAttempts = 5,
backoff = #Backoff(delay = 500))
public List<ResultDto> getSomeResource () {}
Here the RetryCheckerService encapsulates all needed logic.
#Service
public class RetryCheckerService {
public static final String EXPRESSION = "#retryCheckerService.shouldRetry(#root)";
public boolean shouldRetry(WebClientException ex) {
if (ex instanceof WebClientResponseException responseException) {
return responseException.getStatusCode().is5xxServerError()
|| responseException.getStatusCode().equals(HttpStatus.NOT_FOUND);
}
if (ex instanceof WebClientRequestException requestException) {
String message = requestException.getMessage();
if (message == null) {
return false;
}
return message.contains("HttpConnectionOverHTTP");
}
return false;
}
}