Response object, either returned by the synchronous
performRequest methods or
received as an argument in
ResponseListener#onSuccess(Response), wraps the
response object returned by the http client and exposes some additional information.
Response response = restClient.performRequest("GET", "/"); RequestLine requestLine = response.getRequestLine(); HttpHost host = response.getHost(); int statusCode = response.getStatusLine().getStatusCode(); Header headers = response.getHeaders(); String responseBody = EntityUtils.toString(response.getEntity());
Information about the performed request
The host that returned the response
The response status line, from which you can for instance retrieve the status code
The response headers, which can also be retrieved by name though
The response body enclosed in an
When performing a request, an exception is thrown (or received as an argument
ResponseListener#onFailure(Exception) in the following scenarios:
- communication problem (e.g. SocketTimeoutException)
- a response was returned, but its status code indicated
an error (not
ResponseExceptionoriginates from a valid http response, hence it exposes its corresponding
Responseobject which gives access to the returned response.
ResponseException is not thrown for
HEAD requests that return
404 status code because it is an expected
HEAD response that simply
denotes that the resource is not found. All other HTTP methods (e.g.,
404 responses unless the
ignore is a special client parameter that doesn’t get sent
to Elasticsearch and contains a comma separated list of error status codes.
It allows to control whether some error status code should be treated as an
expected response rather than as an exception. This is useful for instance
with the get api as it can return
404 when the document is missing, in which
case the response body will not contain an error but rather the usual get api
response, just without the document as it was not found.
Note that the low-level client doesn’t expose any helper for json marshalling and un-marshalling. Users are free to use the library that they prefer for that purpose.
The underlying Apache Async Http Client ships with different
implementations that allow to provide the request body in different formats
(stream, byte array, string etc.). As for reading the response body, the
HttpEntity#getContent method comes handy which returns an
reading from the previously buffered response body. As an alternative, it is
possible to provide a custom
that controls how bytes are read and buffered.