junit tests with flying saucer

I don't know hoe should I make thi unit test, can you please help me?

public void htmlToPdf(final String pHtml, final HttpServletResponse pResponse) throws IOException {
        if (pHtml != "") {
            final ITextRenderer renderer = new ITextRenderer();
            renderer.setDocumentFromString(pHtml);
            renderer.setPDFVersion(new Character(PdfWriter.VERSION_1_7));
            final ServletOutputStream out = pResponse.getOutputStream();
            try {
                renderer.layout();
                renderer.createPDF(out);
                out.flush();
                out.close();
            } catch (final DocumentException e) {
                pResponse.setStatus(500);
            } catch (final Exception e) {
                pResponse.setStatus(404);
            } finally {
                if (out != null) {
                    try {
                        out.close();
                    } catch (final IOException e) {
                        // ignore
                    }
                }
            }
        }

I don't really know how I have to do it. I need to have 100 coverage..