Opera provides web based simulator which you can use to test your web pages in Opera Mini. Opera Mini is based on Java, on both mobile and in the simulator, so Java plug-in is needed.
If you don’t have an public IP address you are firewalled you need to do a port forward with SSH tunnel though a server having public IP:
ssh -gNR 8888:localhost:8888 yourserver.com
Then you just go to Opera Mini simulator and type your port forwarded address: