Is manual closing required when using Apache HttpClient's execute method?

Question

I'm currently working with Apache HttpClient for executing HTTP requests in my Java application. I've come across different examples and snippets where the handling of closing responses varies, and it has left me a bit confused about the best practices for resource management with this library.

From my understanding, when using the execute method of HttpClient, it seems like the response resources are automatically managed in some contexts, especially when using response handlers. For example, when employing a HttpClientResponseHandler with the execute method, it looks like the library takes care of closing the response for you:

HttpResponse response = httpClient.execute(httpGet, responseHandler);

However, I've seen other code examples where developers manually close the response, even when using similar patterns:

CloseableHttpResponse response = httpClient.execute(httpGet);
try {
    // Process the response
} finally {
    response.close();
}

This is the execute method in org.apache.hc.client5.http.impl.classic.CloseableHttpClient. The response is in a try-with block

public <T> T execute(
            final HttpHost target,
            final ClassicHttpRequest request,
            final HttpContext context,
            final HttpClientResponseHandler<? extends T> responseHandler) throws IOException {
        Args.notNull(responseHandler, "Response handler");

        try (final ClassicHttpResponse response = doExecute(target, request, context)) {
            try {
                final T result = responseHandler.handleResponse(response);
                final HttpEntity entity = response.getEntity();
                EntityUtils.consume(entity);
                return result;
            } catch (final HttpException t) {
                // Try to salvage the underlying connection in case of a protocol exception
                final HttpEntity entity = response.getEntity();
                try {
                    EntityUtils.consume(entity);
                } catch (final Exception t2) {
                    // Log this exception. The original exception is more
                    // important and will be thrown to the caller.
                    LOG.warn("Error consuming content after an exception.", t2);
                }
                throw new ClientProtocolException(t);
            }
        }
    }

Given the above, my questions are:

1. When using Apache HttpClient's execute method with a response handler, is it necessary to manually close the response, or does the library handle it for you?
2. If the library does handle closing, does this apply to all types of responses, including those from CloseableHttpClient and HttpClient with response handlers?

I'm looking for guidance on best practices to ensure proper resource management while avoiding memory leaks or resource exhaustion in my applications.

Thank you in advance for your insights and assistance!

Edit: No, My question is not similar to the suggested answer as I am using httpclient5-5.2.1 and not httpclient 4.5.x

Edit2: And you wonder why people prefer to work with ChatGpt.

Answer 1

Yes.

You can use try-with-resources to make your code more clear.

try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
    // Process the response
}

You can take a look at this article to get more details.