How to disable all network connections in Java
Is there any way to run Java VM (Java. Exe) on Windows Server 2008 and disable all network connections using command line parameters or system variables?
Solution
You can do this by enabling the default Java security manager By default, no security is enforced, so you can perform any action, but if security manager is enabled, network access, file access and many other actions will be restricted unless you specify otherwise in the security policy file
To enable the default security manager, pass this parameter to the JVM at startup
java -Djava.security.manager=default my.main.Class
By doing so, any attempt to access the network from within the JVM will throw a Java net. NetPermission.
This will also destroy file access and other contents, so if you need to allow it, you need to specify them in a special security policy file (- DJava. Security. Policy = path / to / policy. File) There should be many examples of how to set it. Just search "Java permission" to start using it