java.io.IOException: Attempted read from closed stream

What does EntityUtils.toString(postResponse.getEntity()) do with the response entity? I would suspect, that it is consuming the entity's content stream. The HttpClient javadoc states, that only entities, which are repeatable can be consumed more than once. Therefore if the entity is not repeatable you cannot feed the content stream to the mapper again. To avoid this you should only let the mapper consume the stream - if logging of content is required, log the parsed Response object.

I had the same problem. Make sure you aren't consuming the entity's content stream in the "watch" or "inspect" section of your IDE. It's closed after it's consumed (read).

And sorry for my english.

I found an answer for similar issue with Spring RestTemplate here : https://www.baeldung.com/spring-rest-template-interceptor

if we want our interceptor to function as a request/response logger, then we need to read it twice – the first time by the interceptor and the second time by the client. The default implementation allows us to read the response stream only once. To cater such specific scenarios, Spring provides a special class called BufferingClientHttpRequestFactory. As the name suggests, this class will buffer the request/response in JVM memory for multiple usage.

Here's how the RestTemplate object is initialized using BufferingClientHttpRequestFactory to enable the request/response stream caching:

RestTemplate restTemplate = new RestTemplate( new BufferingClientHttpRequestFactory( new SimpleClientHttpRequestFactory() ) );