connection reset on my websphere - connection

Question

I'm trying to connect to a host. The error "connection reset" always occurs in the websphere.
As a self-written Java project without websphere it works with the identical code. The
error does not occur. I suspect that the websphere and the ciphersuite "TLS ... SHA386" don't
work together. But when setting the socket no error occurs. Can someone help me?
I work with:
websphere v8.5.5.11
java-sdk 1.8.64_bundled
and here my Java-Code:
#Singleton
#Startup
public class ClientStart {
#PostConstruct
public void startClient(){
try {
testHttp();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
void testHttp() throws Exception {
String token24h = "eyJhbGci ... 95BBo7PVej8uXdw9sA";
String url = "https:// ... /apserver/api/products/111234568408/packs/U1Q0MUFHUEdHMExXQUo=?ctx=f2a98d0d-9d06-45e3-8f58-87f9d3cfcb06&lot=QlRFNEdBTQ==&exp=310822&pcs=PPN&sid=07758c03-d265-454d-8544-6d0e2ca29d53";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
SSLSocketFactory socketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
SSLSocket sslsocket = (SSLSocket) SSLSocketFactory.getDefault().createSocket();
sslsocket.setEnabledCipherSuites(new String[]{
"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384"
});
con.setSSLSocketFactory(socketFactory);
//create Request-Header aufbauen
con.setRequestMethod("GET");
con.setRequestProperty(HttpHeaders.AUTHORIZATION, "Bearer " + token24h);
con.setRequestProperty(HttpHeaders.CACHE_CONTROL,"no-cache");
con.setRequestProperty(HttpHeaders.ACCEPT,"application/json");
con.setRequestProperty(HttpHeaders.ACCEPT_ENCODING,"application/json");
int responseCode = con.getResponseCode();
//TODO other things
}
After step con.getResponseCode() appears this Stacktrace
[31.03.18 16:49:09:269 CEST] 00000054 SystemErr R java.net.SocketException: Connection reset
[31.03.18 16:49:09:269 CEST] 00000054 SystemErr R at java.net.SocketInputStream.read(SocketInputStream.java:220)
[31.03.18 16:49:09:285 CEST] 00000054 SystemErr R at java.net.SocketInputStream.read(SocketInputStream.java:152)
[31.03.18 16:49:09:285 CEST] 00000054 SystemErr R at com.ibm.jsse2.a.a(a.java:79)
[31.03.18 16:49:09:285 CEST] 00000054 SystemErr R at com.ibm.jsse2.a.a(a.java:182)
Please help me. Thanks.