Httpclient 4, error 302. How to redirect?
Solution 1
For 4.1 version:
DefaultHttpClient httpclient = new DefaultHttpClient();
httpclient.setRedirectStrategy(new DefaultRedirectStrategy() {
public boolean isRedirected(HttpRequest request, HttpResponse response, HttpContext context) {
boolean isRedirect=false;
try {
isRedirect = super.isRedirected(request, response, context);
} catch (ProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (!isRedirect) {
int responseCode = response.getStatusLine().getStatusCode();
if (responseCode == 301 || responseCode == 302) {
return true;
}
}
return isRedirect;
}
});
Solution 2
For HttpClient 4.3.x :
HttpClient httpClient = HttpClientBuilder.create().setRedirectStrategy(new LaxRedirectStrategy()).build();
Solution 3
In later versions of HttpCLient (4.1+), you can just do this:
DefaultHttpClient client = new DefaultHttpClient()
client.setRedirectStrategy(new LaxRedirectStrategy())
LaxRedirectStrategy will automatically redirect HEAD, GET, and POST requests. For a stricter implementation, use DefaultRedirectStrategy.
Solution 4
You have to implement custom redirection handler that will indicate that response to POST is a redirection. This can be done by overriding isRedirectRequested() method as shown below.
DefaultHttpClient client = new DefaultHttpClient();
client.setRedirectHandler(new DefaultRedirectHandler() {
@Override
public boolean isRedirectRequested(HttpResponse response, HttpContext context) {
boolean isRedirect = super.isRedirectRequested(response, context);
if (!isRedirect) {
int responseCode = response.getStatusLine().getStatusCode();
if (responseCode == 301 || responseCode == 302) {
return true;
}
}
return isRedirect;
}
});
In later version of HttpClient, the class name is DefaultRedirectStrategy, but similar solution can be used there.
Solution 5
httpclient.setRedirectHandler(new DefaultRedirectHandler());
See HttpClient Javadoc
juanmirocks
Senior Developer / PhD in Computer Science and Text Mining
Updated on July 09, 2022Comments
-
juanmirocks almost 2 years
I want to access one site that first requires an (tomcat server) authentication and then log in with a POST request and keep that user to see the site's pages. I use Httpclient 4.0.1
The first authentication works fine but not the logon that always complains about this error: "302 Moved Temporarily"
I keep cookies & I keep a context and yet nothing. Actually, it seems that the logon works, because if I write incorrect parameters or user||password, I see the login page. So I guess what doesn't work is the automatic redirection.
Following my code, which always throws the IOException, 302:
DefaultHttpClient httpclient = new DefaultHttpClient(); CookieStore cookieStore = new BasicCookieStore(); httpclient.getParams().setParameter( ClientPNames.COOKIE_POLICY, CookiePolicy.BROWSER_COMPATIBILITY); HttpContext context = new BasicHttpContext(); context.setAttribute(ClientContext.COOKIE_STORE, cookieStore); //ResponseHandler<String> responseHandler = new BasicResponseHandler(); Credentials testsystemCreds = new UsernamePasswordCredentials(TESTSYSTEM_USER, TESTSYSTEM_PASS); httpclient.getCredentialsProvider().setCredentials( new AuthScope(AuthScope.ANY_HOST, AuthScope.ANY_PORT), testsystemCreds); HttpPost postRequest = new HttpPost(cms + "/login"); List<NameValuePair> formparams = new ArrayList<NameValuePair>(); formparams.add(new BasicNameValuePair("pUserId", user)); formparams.add(new BasicNameValuePair("pPassword", pass)); postRequest.setEntity(new UrlEncodedFormEntity(formparams, "UTF-8")); HttpResponse response = httpclient.execute(postRequest, context); System.out.println(response); if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK) throw new IOException(response.getStatusLine().toString()); HttpUriRequest currentReq = (HttpUriRequest) context.getAttribute( ExecutionContext.HTTP_REQUEST); HttpHost currentHost = (HttpHost) context.getAttribute( ExecutionContext.HTTP_TARGET_HOST); String currentUrl = currentHost.toURI() + currentReq.getURI(); System.out.println(currentUrl); HttpEntity entity = response.getEntity(); if (entity != null) { long len = entity.getContentLength(); if (len != -1 && len < 2048) { System.out.println(EntityUtils.toString(entity)); } else { // Stream content out } }