If you look at section 9.3.1 in the developers guide found here:

http://api.openoffice.org/docs/DevelopersGuide/Drawing/Drawing.xhtml

The following example code is incorrect:

  XDrawPage xDrawPage = (XDrawPage)xDrawPages.getByIndex(nIndex);

and should be:

  XDrawPage xDrawPage =
(XDrawPage)UnoRuntime.queryInterface(XDrawPage.class,xDrawPages.getByIndex(nIndex));


This type of problem can be found everywhere in the docs.  For example, on the
same page under the section:

Glue Points and Connectors

The 3rd line of code reads:

  XPage xDrawPages.getByIndex( 0 );

which won't even compile.