An error is reported for cross-origin access to an httpclient4 instance. Who knows under what circumstances?

The error is as follows:

Org. Apache. http. Client. clientprotocolexception

At org.apache.http.impl.client.?acthttpclient.exe cute (abstracthttpclient. Java: 909)
At org.apache.http.impl.client.?acthttpclient.exe cute (abstracthttpclient. Java: 1066)
At org.apache.http.impl.client.?acthttpclient.exe cute (abstracthttpclient. Java: 1044)
At org.apache.http.impl.client.?acthttpclient.exe cute (abstracthttpclient. Java: 1035)
At com. qqweibo O. qqnotify. getmethod (qqnotify. Java: 166)
At com. qqweibo O. jiami. Get (jiami. Java: 89)
At com. qqweibo O. qqnotify. getoauthverifier (qqnotify. Java: 82)
At com. Tencent. Weibo. example. testqqweibo. Main (testqqweibo. Java: 19)
Caused by: org. Apache. http. httpexception: unable to establish route: Planned ={}-> http://xxx.com; current ={}-> http://yyy.com
At org. Apache. http. impl. Client. defaultrequestdiredire. establishroute (defaultrequestdire. Java: 842)
At org. Apache. http. impl. Client. defaultrequestdire. tryconnect (defaultrequestdire. Java: 645)
At org.apache.http.impl.client.defaultrequestdirector.exe cute (defaultrequestdire. Java: 480)
At org.apache.http.impl.client.?acthttpclient.exe cute (abstracthttpclient. Java: 906)

... 7 more

After temporary processing, I rebuilt an httpclient4 instance for request.