[ 
https://issues.apache.org/jira/browse/HTTPCORE-437?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15608082#comment-15608082
 ] 

Adam Michalik edited comment on HTTPCORE-437 at 10/26/16 10:40 AM:
-------------------------------------------------------------------

# That might be an issue in the [Sardine|https://github.com/lookfirst/sardine] 
WebDAV library that I'm actually using and that in turn uses HttpClient. I see 
that for each request done with the HttpClient, the same instance of 
{{HttpClientContext}} is passed. But the context class is marked as 
{{@NotThreadSafe}} and the instance is mutated during the execution of the 
request. I raised an issue on the Sardine project: 
https://github.com/lookfirst/sardine/issues/263
# The system itself is running on Spring and the HttpClient instance is a 
Spring bean, but I don't see a way for it to influence the low-level processing 
inside HttpClient
# I added the environment info to the issue - Oracle JDK 8u101 on Ubuntu 14.04


was (Author: hattifnat):
# That might be an issue in the [Sardine|https://github.com/lookfirst/sardine] 
WebDAV library that I'm actually using and that in turn uses HttpClient. I see 
that for each request done with the HttpClient, the same instance of 
{{HttpClientContext}} is passed. But the context class is marked as 
{{@NotThreadSafe}} and the instance is mutated during the execution of the 
request. I will raise an issue on the Sardine project and reference it here.
# The system itself is running on Spring and the HttpClient instance is a 
Spring bean, but I don't see a way for it to influence the low-level processing 
inside HttpClient
# I added the environment info to the issue - Oracle JDK 8u101 on Ubuntu 14.04

> NullPointerException in HeaderGroup.getHeaders
> ----------------------------------------------
>
>                 Key: HTTPCORE-437
>                 URL: https://issues.apache.org/jira/browse/HTTPCORE-437
>             Project: HttpComponents HttpCore
>          Issue Type: Bug
>          Components: HttpCore
>    Affects Versions: 4.4.5
>         Environment: Oracle JDK 8u101 on Ubuntu 14.04
>            Reporter: Adam Michalik
>
> I'm using HttpClient in multithreaded environment with 
> PoolingHttpClientConnectionManager. Once in a while I get an exception whose 
> root cause is
> {code}
>     Caused by: java.lang.NullPointerException: null
>         at 
> org.apache.http.message.HeaderGroup.getHeaders(HeaderGroup.java:182)
>         at 
> org.apache.http.message.AbstractHttpMessage.getHeaders(AbstractHttpMessage.java:73)
>         at 
> org.apache.http.impl.client.DefaultClientConnectionReuseStrategy.keepAlive(DefaultClientConnectionReuseStrategy.java:51)
>         at 
> org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:274)
>         at 
> org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
>         at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
>         at 
> org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
>         at 
> org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
>         at 
> org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:71)
>         at 
> org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:220)
>         at 
> org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:164)
> {code}
> The {{getHeaders}} method is 
> {code:java}
>     public Header[] getHeaders(final String name) {
>         List<Header> headersFound = null;
>         for (int i = 0; i < this.headers.size(); i++) {
>             final Header header = this.headers.get(i);
>             if (header.getName().equalsIgnoreCase(name)) { // NPE HERE
>                 if (headersFound == null) {
>                     headersFound = new ArrayList<Header>();
>                 }
>                 headersFound.add(header);
>             }
>         }
>         return headersFound != null ? headersFound.toArray(new 
> Header[headersFound.size()]) : EMPTY;
>     }
> {code}
> I looked around in the {{HeaderGroup}} class and I see that every 
> modification to the {{headers}} list has a null-check. Also, the 
> {{BasicHeader}} and {{BufferedHeader}} have null-checks so that {{name}} 
> cannot be null. How can this be occurring?
> The issue happens on production, around 10 exceptions in the last 12 hours 
> out of 1 000 000 requests done in total.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to