java cannot find main class due to security policy

Question

I am running a java app as follows and my policy file is in the same folder and it gives the following error. if I run it without specifying policy related parameters, it runs fine. any idea what I am doing wrong here and how to fix it? thanks.

Error: Could not find or load main class –Djava.security.policy==quantanywhere.policy

java -Djava.security.manager –Djava.security.policy==my.policy -jar myapp.jar

my.policy file contents:

grant {
    permission java.security.AllPermission;
};

Answer 1

i got it..

#1 create a policy file and give all permissions

grant {
    permission java.security.AllPermission "", "";
};

#2 specify that policy file in command line

-Djava.security.manager -Djava.security.policy==/path/my.policy

#3 create a custom security manager class

public class MySecurityManager extends SecurityManager
{
    @Override
    public void checkExec(String cmd) 
    {
        throw new RuntimeException( "Cannot execute shell script" );
    }
}

#4 activate your custom security manager

    SecurityManager securityManager = new MySecurityManager();
    
    System.setSecurityManager( securityManager );

#5 that's it. your app can no longer execute shell commands/scripts