System.out/err cannot be redirected in a sandboxed**
application(/applet).

Assuming you wanted to to show the end user the
System.out/System.err from a *sandboxed* app.*, how
would you go about collecting the information?

* Note - I am looking at launching apps. written by other
people, so I need to intercept/duplicate the normal
System.out/err they might use.  The GUI might be
invoked by a 'full trust' app. - then the task is easy,
*but otherwise,* is there a (sandboxed) way to intercept
those streams?

**This (sandboxed) Applet is not allowed to set the
output stream..

<sscce>
import java.applet.Applet;
import java.awt.Label;
import java.io.PrintStream;
import java.io.ByteArrayOutputStream;

public class RedirectOutputInApplet extends Applet {

 public void init() {
   try {
     PrintStream ps = new PrintStream(
       new ByteArrayOutputStream());
     System.setOut(ps);
   }  catch(Throwable t) {
     add(new Label(t.getMessage())  );
   }
 }
}
</sscce>