从inputstream中读pdf生成pdf文件

public static void main(String[] args) {
        System.out.println(FileUtils.exists("invoice/2017011817151260118001.pdf"));
        System.out.println(FileUtils.exists("invoice/20170118/2017011817151260118001.pdf"));
        InputStream inputStream=FileUtils.getFileStream("invoice/20170118/2017011817151260118001.pdf");//从服务器上读dpf文件
        byte[] b = new byte[1024];
        int a=0;
        try {
            //FileOutputStream fo = new FileOutputStream("D:/test/a.pdf");
            FileOutputStream fo = new FileOutputStream("D:/test/wj.pdf");
           // String str=convertStreamToString(inputStream);
            //Document document = new Document();
//            while((a = inputStream.read(b)) != -1){
//                fo.write(a);
//
//            }
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            for(int i;(i=inputStream.read())!=-1;)
            {
                baos.write(i);
            }
            baos.flush();
            Document doc = new Document();
            PdfStream pdfStream=new PdfStream(baos.toByteArray());

            PdfWriter pw =PdfWriter.getInstance(doc, fo);  //
            pdfStream.toPdf(pw,fo);
            System.out.println(doc.newPage());
            pw.flush();
            baos.close();

            pw.close();

            fo.close();
            //doc.close();
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (DocumentException e) {
            e.printStackTrace();
        }
        System.out.println();
    }