Java中的PDF加密格式不匹配

每当我使用PDFWriter加密将字节数组转换为pdf时，就获得以下格式。有人可以帮忙找到以下格式吗？

%PDF-1.5 % 1 0 obj <</Type/Catalog/Pages 2 0 R/Lang(en-MY) >> endobj 2 0 obj <</Type/Pages/Count 7/Kids[ 3 0 R 25 0 R 27 0 R 29 0 R 33 0 R 37 0 R 39 0 R] >> endobj 3 0 obj <</Type/Page/Parent 2 0 R/Resources<</Font<</F1 5 0 R/F2 11 0 R/F3 13 0 R/F4 18 0 R/F5 23 0 R>>/ExtGState<</GS7 7 0 R/GS8 8 0 R>>/XObject<</Meta9 9 0 R>>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.32 841.92] /Contents 4 0 R/Group<</Type/Group/S/Transparency/CS/DeviceRGB>>/Tabs/S>> endobj 4 0 obj <</Filter/FlateDecode/Length 6445>> stream x=ks8SOWC<Inq}Tf77}Vlg$yD-5KTh4FUU)"3- ZfWCvO_x)2!Bg_B"YYYYOw_fMg7r'•O••=_v, OMSkDo^ˇH,H$T)|p?kZ)T*9Eit^6t)d.t]evVg}OkSj/35? ÇTM63Ii=_M4=lj'k|_L%TNnS1)Y\Nqp
gs[}D/SQL63yO000C(Nl|uc\y=WfB9L"/ZOVuT|uzB"eprScF' NM! 下面的代码用于加密

PdfWriter writer = PdfWriter.getInstance(document, bos); writer.setEncryption("test".getBytes(), "test".getBytes(),PdfWriter.ALLOW_PRINTING, PdfWriter.ALLOW_COPY); document.open(); document.add(new Paragraph(org.apache.commons.io.IOUtils.toString(Base64.getDecoder().decode(sAttachBase64.getBytes())))); document.close(); dataSource = new ByteArrayDataSource(bos.toByteArray(), "application/pdf");