Convert HttpResponse to byte array

Question

I have

 HttpResponse response = httpclient.execute(httpget);

my method can transfer byte[] over sockets on device and PC, so how can i convert HttpResponse into byte[] and than back to HttpResponse?

Answer 1

It is not easy.

If you simply wanted the body of the response, then you could do this to grab it

 ByteArrayOutputStream baos = new ByteArrayOutputStream();
 response.getEntity().writeTo(baos);
 byte[] bytes = baos.toByteArray();

Alternatively:

 byte[] bytes = EntityUtils.toByteArray(response.getEntity());

Then you could add the content to another HttpResponse object as follows:

 HttpResponse response = ...
 response.setEntity(new ByteArrayEntity(bytes));

---

But that's probably not good enough because you most likely need all of the other stuff in the original response; e.g. the status line and the headers (including the original content type and length).

If you want to deal with the whole response, you appear to have two choices:

• You could pick the response apart (e.g. getting the status line, iterating the headers) and manually serialize, then do the reverse at the other end.

• You can use HttpResponseWriter to do the serializing and HttpResponseParser to rebuild the response at the other end. This is explained here.

Answer 2

With java11:

var client = HttpClient.newBuilder().build();
var request = HttpRequest.newBuilder()
 .uri(URI.create("https://yourdomain.test")).GET().build();
HttpResponse<byte[]> response = client.send(request, HttpResponse.BodyHandlers.ofByteArray());
if (200 == response.statusCode()) {
 byte[] bytes = response.body();
}

Answer 3

you need to get it as a stream: response.getEntity().getContent()

then you can directly read the stream into a byte[].

• chehom: Thank you with it i find good method (EntityUtils.toByteArray(entity)), but there is still problem to convert byte[] in HttpEntity.