HttpClient的4，302错误怎么重定向？ [英] Httpclient 4, error 302. How to redirect?

问题描述

我要访问的第一需要（Tomcat服务器）身份验证一个网站，然后用POST请求登录并保持用户看到网站的网页。我使用的HttpClient 4.0.1

第一认证工作正常，但不能登录总是抱怨这个错误：302临时移动

我把饼干和放大器;我把一个上下文，但一无所获。事实上，似乎登录的作品，因为如果我写不正确的参数或用户密码||，我看到登录页面。所以我猜什么行不通是自动重定向。

随着我的code，它总是抛出IOException异常，302：

  DefaultHttpClient的HttpClient =新DefaultHttpClient（）;
    的CookieStore的CookieStore =新BasicCookieStore（）;
    httpclient.getParams（）的setParameter（
      ClientPNames.COOKIE_POLICY，CookiePolicy.BROWSER_COMPATIBILITY）;
    HttpContext的背景下=新BasicHttpContext（）;
    context.setAttribute（ClientContext.COOKIE_STORE，的CookieStore）;
    // ResponseHandler所＆LT;串GT; ResponseHandler所=新BasicResponseHandler（）;    凭据testsystemCreds =新UsernamePasswordCredentials（TESTSYSTEM_USER，TESTSYSTEM_PASS）;
    httpclient.getCredentialsProvider（）。setCredentials方法（
            新AuthScope（AuthScope.ANY_HOST，AuthScope.ANY_PORT）
            testsystemCreds）;    HttpPost postRequest =新HttpPost（CMS +/登录）;
    清单＆LT;＆的NameValuePair GT; formparams =新的ArrayList＆LT;＆的NameValuePair GT;（）;
    formparams.add（新BasicNameValuePair（pUserId用户））;
    formparams.add（新BasicNameValuePair（pPassword，通））;
    postRequest.setEntity（新UrlEn codedFormEntity（formparams，UTF-8））;
    HTT presponse响应= httpclient.execute（postRequest，背景）;
    的System.out.println（响应）;    如果（response.getStatusLine（）的getStatus code（）！= HttpStatus.SC_OK）
        抛出新IOException异常（response.getStatusLine（）的toString（））;    HttpUriRequest currentReq =（HttpUriRequest）context.getAttribute（
            ExecutionContext.HTTP_REQUEST）;
    HttpHost currentHost =（HttpHost）context.getAttribute（
            ExecutionContext.HTTP_TARGET_HOST）;
    串CURRENTURL = currentHost.toURI（）+ currentReq.getURI（）;
    的System.out.println（CURRENTURL）;    HttpEntity实体= response.getEntity（）;
    如果（实体！= NULL）{
        长LEN = entity.getContentLength（）;
        如果（LEN = -1＆安培;！＆放大器; LEN＆LT; 2048）{
            的System.out.println（EntityUtils.toString（实体））;
        }其他{
            //流出来的内容
        }
    }
 

解决方案

有关4.1版：

  DefaultHttpClient的HttpClient =新DefaultHttpClient（）;
    httpclient.setRedirectStrategy（新DefaultRedirectStrategy（）{
        公共布尔isRedirected（HTT prequest请求的Htt presponse响应，HttpContext的背景下）{
            布尔isRedirect = FALSE;
            尝试{
                isRedirect = super.isRedirected（请求，响应上下文）;
            }赶上（的ProtocolException E）{
                // TODO自动生成catch块
                e.printStackTrace（）;
            }
            如果（！isRedirect）{
                。INT响应code = response.getStatusLine（）的getStatus code（）;
                如果（响应code == || 301响应code == 302）{
                    返回true;
                }
            }
            返回isRedirect;
        }
    }）;
 

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
        }
    }

解决方案

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;
        }
    });

这篇关于HttpClient的4，302错误怎么重定向？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！