There are 2 things you need to do.
1. Get the system security manager to do accept your permission checks. Here are 2 examples :
Replace xxx.xxx.xxx.xxx with the server IP address.
The RunTime is for a thread (obviously).
Put the needed lines as your first code in the main method.
2. You have to sign the JAR file
Fill out all this information. It will create a keystore named "keystore" (you can change it to whatever name you would like)
ii. Put a certificate on it. You could pay to have it certificated or sign it yourself :
NOTE: Remember the passwords you put in these.
“Don’t worry if it doesn’t work right. If everything did, you’d be out of a job.” (Mosher's Law of Software Engineering)
“If debugging is the process of removing bugs, then programming must be the process of putting them in.” (Edsger Dijkstra)
If you signed the applet and all external libraries (jars), you do not need to write permission checking code.
Remember to sign external jars as well, not only the Applet jar itself. I had permission exception problem and had not figured out until I found some external jars were not signed. I signed all of them then everything was fine.