I have an existing jrxml document in iReport Designer, which is horizontal, and I need to add another page, which has to be vertical, to this existing document. Is this possible? Can I do it in one document? Or is it somehow possible to make separate jrxml document and then join both documents using Java (I am generating the documents inside a Java application)?
Not possible with iReport but with Jaspersoft Studio, it's possible using books. There's a sample in demo/samples/book in JasperReports library source.
The first page is horizontal while the second page is vertical.