We too had same issue and we did all following things.
- Reimported Server SSL certificates.
- Made sure weblogic is using the proper caecerts.
Finally our weblogic enabled weblogic DEBUG mode and found there is "NOT HANDSHAKED" exception.
Reason we found is , client system is using jdk 1.6 and server is using higher jdk version ( 1.8) because of which there is some TLS version mismatch causing the issue.
Weblogic team tweaked server configuration by adding following lines in server arguments.
-Djdk.tls.client.protocol=TLSv1.2 -DUseSunHttpHandler=true.