How to disable Java security manager?

Question

Is there any way to completely disable Java security manager?

I'm experimenting with source code of db4o. It uses reflection to persist objects and it seems that security manager doesn't allow reflection to read and write private or protected fields.

My code:

public static void main(String[] args) throws IOException {
    System.out.println("start");
    new File( DB_FILE_NAME ).delete();
    ObjectContainer container = Db4o.openFile( DB_FILE_NAME );
    String ob = new String( "test" );
    container.store( ob );
    ObjectSet result = container.queryByExample( String.class );
    System.out.println( "retrieved (" + result.size() + "):" );
    while( result.hasNext() ) {
        System.out.println( result.next() );
    }
    container.close();
    System.out.println("finish");
}

Output:

start
[db4o 7.4.68.12069   2009-04-18 00:21:30] 
 AccessibleObject#setAccessible() is not available. Private fields can not be stored.
retrieved (0):
finish

This thread suggests modifying java.policy file to allow reflection but it doesn't seem to work for me.

I'm starting JVM with arguments
-Djava.security.manager -Djava.security.policy==/home/pablo/.java.policy
so specified policy file will be the only policy file used

The file looks like this:

grant {
    permission java.security.AllPermission;
    permission java.lang.reflect.ReflectPermission "suppressAccessChecks";
};

I spent last 3 hrs on this and don't have any ideas how to make this work. Any help appreciated.

Answer 1

You could try adding this to the main() of your program:

System.setSecurityManager(null);

Worked for me for a "trusted" WebStart application when I was having security manager issues. Not sure if it will work for your db4o case, but it might be worth a try.

EDIT: I'm not suggesting that this is a general solution to security manager problems. I was just proposing it as a way to help debug the original poster's problem. Clearly, if you want to benefit from a security manager then you should not disable it.