When I get just a Class object for "sun.tools.jconsole.OutputViewer" I also get a side effect: it launches jconsole. And current thread is waiting when jconsole will be closed by a user.
Such behavior is unexpected when I call Class.forName.

The code

public class JConsoleTest {
    public static void main(String[] args) {
        try {
            Class aClass = Class.forName("sun.tools.jconsole.OutputViewer");
            System.out.println(aClass);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}