Invoke WebService using Apex ( with/without Authorization) using Apex
Add your **Endpoint URL** in **remote site settings** as shownNavigation: Setup -> Security Controls -> Remote site Settings
Save Remote Site settings lets consider **Apex__gen__class** as **wsdl**
generated classDon't know how to generate **Apex Class** from **WSDL** click
here
[https://www.salesforce.com/us/