How set Response body in javax.ws.rs.core.Response

There is a REST API endpoint which needs to be implemented is used to get some information and send backend request to an another server and response which is coming from backend server has to set the to final response. My problem is how to set response body in javax.ws.rs.core.Response?

@Path("analytics")@GET@Produces("application/json")public Response getDeviceStats(@QueryParam("deviceType") String deviceType,                               @QueryParam("deviceIdentifier") String deviceIdentifier,                               @QueryParam("username") String user, @QueryParam("from") long from,                               @QueryParam("to") long to) {    // Trust own CA and all self-signed certs    SSLContext sslcontext = null;    try {        sslcontext = SSLContexts.custom()                .loadTrustMaterial(new File(getClientTrustStoretFilePath()), "password## Heading ##".toCharArray(),                        new TrustSelfSignedStrategy())                .build();    } catch (NoSuchAlgorithmException e) {        log.error(e);    } catch (KeyManagementException e) {        log.error(e);    } catch (KeyStoreException e) {        log.error(e);    } catch (CertificateException e) {        log.error(e);    } catch (IOException e) {        log.error(e);    }    SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(            sslcontext,            new String[] { "TLSv1" },            null,            SSLConnectionSocketFactory.getDefaultHostnameVerifier());    CloseableHttpClient httpclient = HttpClients.custom()            .setSSLSocketFactory(sslsf)            .build();    HttpResponse response = null;    try {        HttpGet httpget = new HttpGet(URL);        httpget.setHeader("Authorization", "Basic YWRtaW46YWRtaW4=");        httpget.addHeader("content-type", "application/json");        response = httpclient.execute(httpget);        String message = EntityUtils.toString(response.getEntity(), "UTF-8");    } catch (ClientProtocolException e) {        log.error(e);    } catch (IOException e) {        log.error(e);    } }  

Here message is the one I need to set. But I tried several methods. Didn't work any of them.