httpclient-stop-follow-redirect
HttpClient 4 – Do Not Follow Redirects
1. Overview
By default, following the HTTP Spec, the HttpClient will automatically follow redirects.
For some usecases, that may be perfectly fine, but there are certainly usecases where that’s not desired – and we’ll now look at how to change that default behavior and stop following redirects.
If you want to dig deeper and learn other cool things you can do with the HttpClient – head on over to the main HttpClient tutorial.
2. Do Not Follow Redirects
In older versions of the Http Client (before 4.3), we can configure what the client does with redirects as follows:
@Test
public void givenRedirectsAreDisabled_whenConsumingUrlWhichRedirects_thenNotRedirected()
throws ClientProtocolException, IOException {
DefaultHttpClient instance = new DefaultHttpClient();
HttpParams params = new BasicHttpParams();
params.setParameter(ClientPNames.HANDLE_REDIRECTS, false);
// HttpClientParams.setRedirecting(params, false); // alternative
HttpGet httpGet = new HttpGet("http://t.co/I5YYd9tddw");
httpGet.setParams(params);
CloseableHttpResponse response = instance.execute(httpGet);
assertThat(response.getStatusLine().getStatusCode(), equalTo(301));
}Notice the alternative API that can be used to configure the redirect behavior without using setting the actual raw http.protocol.handle-redirects parameter:
HttpClientParams.setRedirecting(params, false);Also notice that, with follow redirects disabled, we can now check that the Http Response status code is indeed 301 Moved Permanently – as it should be.
2.2. After HttpClient 4.3
@Test
public void givenRedirectsAreDisabled_whenConsumingUrlWhichRedirects_thenNotRedirected()
throws ClientProtocolException, IOException {
HttpClient instance = HttpClientBuilder.create().disableRedirectHandling().build();
HttpResponse response = instance.execute(new HttpGet("http://t.co/I5YYd9tddw"));
assertThat(response.getStatusLine().getStatusCode(), equalTo(301));
}Note that the new API configures the entire client with this redirect behavior – not just the individual request.
3. Conclusion
This quick tutorial covered how to configure the Apache HttpClient – both pre 4.3 and post – to prevent it from following HTTP redirects automatically.
The implementation of all these examples and code snippets can be found in my github project – this is an Eclipse based project, so it should be easy to import and run as it is.
