[英]java.net.ProtocolException: Server redirected too many times (20)
I've this code:我有这个代码:
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
public class Demo2 {
public static void main(String[] args) {
try {
String url = "http://www......";
URL obj = new URL(url);
HttpURLConnection conn = (HttpURLConnection) obj.openConnection();
conn.setReadTimeout(5000);
conn.addRequestProperty("Accept-Language", "es-ES,es;q=0.8");
conn.addRequestProperty("User-Agent", "Mozilla");
System.out.println("Request URL ... " + url);
boolean redirect = false;
// normally, 3xx is redirect
int status = conn.getResponseCode();
if (status != HttpURLConnection.HTTP_OK) {
if (status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM
|| status == HttpURLConnection.HTTP_SEE_OTHER)
redirect = true;
}
System.out.println("Response Code ... " + status);
if (redirect) {
System.out.println("Redireccionando...");
// get redirect url from "location" header field
String newUrl = conn.getHeaderField("Location");
// get the cookie if need, for login
String cookies = conn.getHeaderField("Set-Cookie");
System.out.println("Galletas: " + cookies);
// open the new connnection again
conn = (HttpsURLConnection) new URL(newUrl).openConnection();
conn.setFollowRedirects(true);
conn.setRequestProperty("Cookie", cookies);
conn.addRequestProperty("Accept-Language", "es-ES,es;q=0.8");
conn.addRequestProperty("User-Agent", "Mozilla");
System.out.println("Redirect to URL : " + newUrl);
}
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer html = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
html.append(inputLine);
}
in.close();
System.out.println("URL Content... \n" + html.toString());
System.out.println("Done");
} catch (Exception e) {
e.printStackTrace();
}
}
}
and result is:结果是:
Request URL ... " http://www.web1.com " Response Code ... 302 Redireccionando... Galletas: 07c18a1bea3520c44535aafeeea31dec07a36313;请求 URL ... " http://www.web1.com " 响应代码 ... 302 Redireccionando ... Galletas: 07c18a1bea3520c44535aafeeea31dec07a36313; path=/ Redirect to URL : " https://www.web2.com " java.net.ProtocolException: Server redirected too many times (20) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1635) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254) at Demo2.main(Demo2.java:58) path=/ 重定向到 URL : " https://www.web2.com " java.net.ProtocolException: 服务器在 sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java) 重定向太多次 (20) :1635) 在 sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254) 在 Demo2.main(Demo2.java:58)
What is the problem?问题是什么? I'm going crazy我要疯了
I also encountered the same issue and this fix, helped me to overcome it.我也遇到了同样的问题,这个修复帮助我克服了它。
before calling the openConnection();
在调用openConnection();
use the following:使用以下内容:
HttpURLConnection.setFollowRedirects(false);
I was facing same issue.我面临同样的问题。 Even I spent quite a lot amount of time to fix this issue.即使我花了很多时间来解决这个问题。 I found out that issue was coming to due following: When you make a call to some JSON services, sometime services might return you data in raw formats or format which may not be typical application/json
.我发现这个问题是由于以下原因造成的:当您调用某些 JSON 服务时,有时服务可能会以原始格式或可能不是典型的application/json
格式返回您的数据。 Your .openConnection()
or InputStreamReader
may not be able to read reponse headers and JSON data.您的.openConnection()
或InputStreamReader
可能无法读取响应头和 JSON 数据。
To fix this issue I tried following and it worked for me:为了解决这个问题,我尝试了以下方法,它对我有用:
Used HttpClient httpClient = new DefaultHttpClient();
使用HttpClient httpClient = new DefaultHttpClient();
instead of (HttpURLConnection) obj.openConnection();
而不是(HttpURLConnection) obj.openConnection();
Set allow circular redirect: httpClient.getParams().setParameter(ClientPNames.ALLOW_CIRCULAR_REDIRECTS, true);
设置允许循环重定向: httpClient.getParams().setParameter(ClientPNames.ALLOW_CIRCULAR_REDIRECTS, true);
Set following post headers which is important:设置以下重要的帖子标题:
httpPost.setHeader("charset","utf-8"); httpPost.setHeader("Accept", "application/json"); httpPost.setHeader("Accept-Language","en-US,en;q=0.8"); httpPost.setHeader("Content-Type", "application/json;charset=UTF-8");
Use StringEntity Read input stream with UTF-8:使用带有 UTF-8 的 StringEntity Read 输入流:
httpresponse.getEntity().getContent(),HTTP.UTF_8), 8);
Here is the sample code which worked for me:这是对我有用的示例代码:
HttpClient httpClient = new DefaultHttpClient();
String url =http://....; httpClient.getParams().setParameter(ClientPNames.ALLOW_CIRCULAR_REDIRECTS, true);
HttpPost httpPost = new HttpPost(url);
httpPost.setHeader("Content-Type", "application/json");
httpPost.setHeader("charset","utf-8");
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Accept-Language","en-US,en;q=0.8");
httpPost.setHeader("Content-Type", "application/json;charset=UTF-8");
//or you can try httpPost.setContentType("application/x-www-form-urlencoded");
StringEntity requestBody = new StringEntity(jsonBody);
requestBody.setContentType("application/json");
httpPost.setEntity(requestBody);
HttpResponse httpresponse = httpClient.execute(httpPost);
org.apache.http.StatusLine statusRespons = httpresponse.getStatusLine();
if (statusRespons.getStatusCode() > 201)
{
errorText = statusRespons.getStatusCode() + " : " + statusRespons.toString() + " : " +statusRespons.getReasonPhrase() ;
}
BufferedReader buffer = new BufferedReader(new InputStreamReader(httpresponse.getEntity().getContent(),HTTP.UTF_8), 8);
String s = "";
while ((s = buffer.readLine()) != null)
jsonString.append(s);
Hope this helps you?希望这对你有帮助?
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