Yes. There is a Java interface that allows you to implement in memory handling of all output.
This is achieved by passing in your own implementation of CustomIO
We have made available the existing code which handles this on which you can base your own implementation. Code at http://files.idrsolutions.com/htmlSrc/org/jpedal/render/output/io/DefaultIO.java.html
You can use this with BuildVu-HTML by calling to the PDFtoHTML5Converter class. Details at http://files.idrsolutions.com/maven/site/buildvu/apidocs/org/jpedal/examples/html/PDFtoHTML5Converter.html#setCustomIO-org.jpedal.render.output.io.CustomIO-
You can use this with BuildVu-SVG by calling to the PDFtoSVGConverter class. Details at https://files.idrsolutions.com/maven/site/buildvu/apidocs/org/jpedal/examples/svg/PDFtoSVGConverter.html#setCustomIO-org.jpedal.render.output.io.CustomIO-