com.lowagie.text.pdf.PdfStamper Java Examples

@Override
public void writeWatermark(String inputFile, String outputFile, Watermark watermark, PageLayout layout) throws Exception {
	try {
		logger.debug("Writing watermark on " + inputFile);
		document = new PdfReader(inputFile);
		try {
			stamper = new PdfStamper(document, new FileOutputStream(outputFile));
			setPageLayout(layout);
			internalWriteWatermark(watermark);
			stamper.close();
		} catch (Exception e) {
			throw new IOException("Unable to write watermark", e);
		}
	} finally {
		if (document != null) {
			document.close();
		}
		if (isEncrypt()) {
			//PdfEncryptor.encrypt(outputFile);
		}
	}
}
 

/**
 * Writes an FDF file and merges it with a PDF form.
 */
@Test
public void main() throws Exception {

	// writing the FDF file
	FdfWriter fdf = new FdfWriter();
	fdf.setFieldAsString("name", "Bruno Lowagie");
	fdf.setFieldAsString("address", "Baeyensstraat 121, Sint-Amandsberg");
	fdf.setFieldAsString("postal_code", "BE-9040");
	fdf.setFieldAsString("email", "[email protected]");
	fdf.setFile(PdfTestBase.RESOURCES_DIR + "SimpleRegistrationForm.pdf");
	fdf.writeTo(PdfTestBase.getOutputStream("SimpleRegistrationForm.fdf"));

	// merging the FDF file
	PdfReader pdfreader = new PdfReader(PdfTestBase.RESOURCES_DIR + "SimpleRegistrationForm.pdf");
	PdfStamper stamp = new PdfStamper(pdfreader, PdfTestBase.getOutputStream("registered_fdf.pdf"));
	FdfReader fdfreader = new FdfReader(PdfTestBase.OUTPUT_DIR + "SimpleRegistrationForm.fdf");
	AcroFields form = stamp.getAcroFields();
	form.setFields(fdfreader);
	stamp.close();

}
 

@Override
public DSSDocument addNewSignatureField(DSSDocument document, SignatureFieldParameters parameters, String pwd) {

	checkDocumentPermissions(document, pwd);
	
	try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
			InputStream is = document.openStream();
			PdfReader reader = new PdfReader(is, getPasswordBinary(pwd))) {

		PdfStamper stp = new PdfStamper(reader, baos, '\0', true);

		stp.addSignature(parameters.getName(), parameters.getPage() + 1, parameters.getOriginX(),
				parameters.getOriginY(), parameters.getWidth(), parameters.getHeight());

		stp.close();

		DSSDocument signature = new InMemoryDocument(baos.toByteArray());
		signature.setMimeType(MimeType.PDF);
		return signature;
	} catch (IOException e) {
		throw new DSSException("Unable to add a signature field", e);
	}
}
 

@Override
protected final void renderMergedOutputModel(
		Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

	// IE workaround: write into byte array first.
	ByteArrayOutputStream baos = createTemporaryOutputStream();

	PdfReader reader = readPdfResource();
	PdfStamper stamper = new PdfStamper(reader, baos);
	mergePdfDocument(model, stamper, request, response);
	stamper.close();

	// Flush to HTTP response.
	writeToResponse(response, baos);
}
 

/**
 *
 * @param template the path to the original form
 * @param list the replacement list
 * @return
 * @throws IOException
 * @throws DocumentException
 */
protected byte[] renameFieldsIn(String template, Map<String, String> list) throws IOException, DocumentException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    // Create the stamper
    PdfStamper stamper = new PdfStamper(new PdfReader(template), baos);
    // Get the fields
    AcroFields fields = stamper.getAcroFields();
    // Loop over the fields
    for (String field : list.keySet()) {
        fields.setField(field, list.get(field));
    }
    // close the stamper
    stamper.close();
    return baos.toByteArray();
}
 

@Override
protected final void renderMergedOutputModel(
		Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

	// IE workaround: write into byte array first.
	ByteArrayOutputStream baos = createTemporaryOutputStream();

	PdfReader reader = readPdfResource();
	PdfStamper stamper = new PdfStamper(reader, baos);
	mergePdfDocument(model, stamper, request, response);
	stamper.close();

	// Flush to HTTP response.
	writeToResponse(response, baos);
}
 

public String cropPdf(String pdfFilePath) throws DocumentException, IOException, Exception {
	String filename = FilenameUtils.getBaseName(pdfFilePath) + "_cropped." + FilenameUtils.getExtension(pdfFilePath);
	filename = FilenameUtils.concat(System.getProperty("java.io.tmpdir"), filename);
	PdfReader reader = new PdfReader(pdfFilePath);
	try {
		PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(filename));
		try {
			for (int i = 1; i <= reader.getNumberOfPages(); i++) {
				PdfDictionary pdfDictionary = reader.getPageN(i);
				PdfArray cropArray = new PdfArray();
				Rectangle box = getSmallestBox(reader, i);
				//Rectangle cropbox = reader.getCropBox(i);
				if (box != null) {
					cropArray.add(new PdfNumber(box.getLeft()));
					cropArray.add(new PdfNumber(box.getBottom()));
					cropArray.add(new PdfNumber(box.getLeft() + box.getWidth()));
					cropArray.add(new PdfNumber(box.getBottom() + box.getHeight()));
					pdfDictionary.put(PdfName.CROPBOX, cropArray);
					pdfDictionary.put(PdfName.MEDIABOX, cropArray);
					pdfDictionary.put(PdfName.TRIMBOX, cropArray);
					pdfDictionary.put(PdfName.BLEEDBOX, cropArray);
				}
			}
			return filename;
		} finally {
			stamper.close();
		}
	} catch (Exception e) {
		logger.error(e.getMessage(), e);
		throw e;
	} finally {
		reader.close();
	}
}
 

/**
 * Merges an XFDF file with a PDF form.
 */
@Test
public void main() throws Exception {

	// merging the FDF file
	PdfReader pdfreader = new PdfReader(PdfTestBase.RESOURCES_DIR + "SimpleRegistrationForm.pdf");
	PdfStamper stamp = new PdfStamper(pdfreader, PdfTestBase.getOutputStream("registered_xfdf.pdf"));
	XfdfReader fdfreader = new XfdfReader(PdfTestBase.RESOURCES_DIR + "register.xfdf");
	AcroFields form = stamp.getAcroFields();
	form.setFields(fdfreader);
	stamp.close();

}
 

/**
 */
public static Map<String, Object> getAcroFieldsFromPdf(DispatchContext dctx, Map<String, ? extends Object> context) {
    Map<String, Object> acroFieldMap = new HashMap<>();
    try {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        Delegator delegator = dctx.getDelegator();
        ByteBuffer byteBuffer = getInputByteBuffer(context, delegator);
        PdfReader r = new PdfReader(byteBuffer.array());
        PdfStamper s = new PdfStamper(r,os);
        AcroFields fs = s.getAcroFields();
        Map<String, Object> map = UtilGenerics.checkMap(fs.getFields());
        s.setFormFlattening(true);

        for (String fieldName : map.keySet()) {
            String parmValue = fs.getField(fieldName);
            acroFieldMap.put(fieldName, parmValue);
        }

    } catch (DocumentException | GeneralException | IOException e) {
        Debug.logError(e, module);
        return ServiceUtil.returnError(e.getMessage());
    }

Map<String, Object> results = ServiceUtil.returnSuccess();
results.put("acroFieldMap", acroFieldMap);
return results;
}
 

@Override
protected final void renderMergedOutputModel(
		Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

	// IE workaround: write into byte array first.
	ByteArrayOutputStream baos = createTemporaryOutputStream();

	PdfReader reader = readPdfResource();
	PdfStamper stamper = new PdfStamper(reader, baos);
	mergePdfDocument(model, stamper, request, response);
	stamper.close();

	// Flush to HTTP response.
	writeToResponse(response, baos);
}
 

@Override
protected final void renderMergedOutputModel(
		Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

	// IE workaround: write into byte array first.
	ByteArrayOutputStream baos = createTemporaryOutputStream();

	PdfReader reader = readPdfResource();
	PdfStamper stamper = new PdfStamper(reader, baos);
	mergePdfDocument(model, stamper, request, response);
	stamper.close();

	// Flush to HTTP response.
	writeToResponse(response, baos);
}
 

public static void main(String args[]) throws Exception {
	FontFactory.register("fonts/fireflysung.ttf"); // fonts/fireflysung.ttf in fireflysung.jar
	Font font = FontFactory.getFont("fonts/fireflysung.ttf", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
	PdfReader pdfReader = new PdfReader("/tmp/ex/test.pdf");
	PdfStamper pdfStamper = new PdfStamper(pdfReader, new FileOutputStream("/tmp/ex/test-out.pdf"));
	addWatermark(pdfStamper, font.getBaseFont(), Color.RED, "測試");
	pdfStamper.close();
}
 

public static void addWatermark(PdfStamper pdfStamper, BaseFont baseFont, Color fontColor, String waterMarkString) throws Exception {
	if (null == pdfStamper || null == baseFont) {
		throw new java.lang.Exception("PdfStamper or BaseFont is null.");
	}
	if (StringUtils.isBlank(waterMarkString)) {
		return;
	}
	PdfContentByte pdfContentByte = null;
	Rectangle pageRect = null;
	PdfGState pdfGState = new PdfGState();
	// 设置透明度为0.4
	pdfGState.setFillOpacity(0.4f);
	pdfGState.setStrokeOpacity(0.4f);
       int pageNum = pdfStamper.getReader().getNumberOfPages();
       try {
           for (int i = 1; i <= pageNum; i++) {
           	pageRect = pdfStamper.getReader().getPageSizeWithRotation(i);
           	// 计算水印X,Y坐标
           	float x = pageRect.getWidth() / 2;
           	float y = pageRect.getHeight() / 2;
           	//获得PDF最顶层
           	pdfContentByte = pdfStamper.getOverContent(i);
           	pdfContentByte.saveState();
           	// set Transparency
           	pdfContentByte.setGState(pdfGState);
           	pdfContentByte.beginText();
           	pdfContentByte.setColorFill(fontColor);
           	pdfContentByte.setFontAndSize(baseFont, 60);
           	// 水印文字成45度角倾斜
           	pdfContentByte.showTextAligned(Element.ALIGN_CENTER, waterMarkString, x, y, 45);
           	pdfContentByte.endText();             	
           }
       } catch (Exception e) {
       	e.printStackTrace();
       } finally {
       	pdfContentByte = null;
           pageRect = null;        	
       }
}
 

@Override
public DSSDocument sign(DSSDocument toSignDocument, byte[] signatureValue, PAdESCommonParameters parameters) {

	checkDocumentPermissions(toSignDocument, parameters.getPasswordProtection());

	try (InputStream is = toSignDocument.openStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
		PdfStamper stp = prepareStamper(is, baos, parameters);
		PdfSignatureAppearance sap = stp.getSignatureAppearance();

		byte[] pk = signatureValue;
		int csize = parameters.getContentSize();
		if (csize < pk.length) {
			throw new DSSException(
					String.format("The signature size [%s] is too small for the signature value with a length [%s]",
							csize, pk.length));
		}

		byte[] outc = new byte[csize];
		System.arraycopy(pk, 0, outc, 0, pk.length);

		PdfDictionary dic = new PdfDictionary();
		dic.put(PdfName.CONTENTS, new PdfString(outc).setHexWriting(true));
		sap.close(dic);

		DSSDocument signature = new InMemoryDocument(baos.toByteArray());
		signature.setMimeType(MimeType.PDF);
		return signature;
	} catch (Exception e) {
		throw new DSSException(e);
	}
}
 

/**
 */
public static Map<String, Object> setAcroFields(DispatchContext dctx, Map<String, ? extends Object> context) {
    Map<String, Object> results = ServiceUtil.returnSuccess();
    Delegator delegator = dctx.getDelegator();
    try {
        Map<String, Object> acroFieldMap = UtilGenerics.checkMap(context.get("acroFieldMap"));
        ByteBuffer byteBuffer = getInputByteBuffer(context, delegator);
        PdfReader r = new PdfReader(byteBuffer.array());
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PdfStamper s = new PdfStamper(r, baos);
        AcroFields fs = s.getAcroFields();
        Map<String, Object> map = UtilGenerics.checkMap(fs.getFields());
        s.setFormFlattening(true);

        for (String fieldName : map.keySet()) {
            String fieldValue = fs.getField(fieldName);
            Object obj = acroFieldMap.get(fieldName);
            if (obj instanceof Date) {
                Date d=(Date)obj;
                fieldValue=UtilDateTime.toDateString(d);
            } else if (obj instanceof Long) {
                Long lg=(Long)obj;
                fieldValue=lg.toString();
            } else if (obj instanceof Integer) {
                Integer ii=(Integer)obj;
                fieldValue=ii.toString();
            }   else {
                fieldValue=(String)obj;
            }

            if (UtilValidate.isNotEmpty(fieldValue)) {
                fs.setField(fieldName, fieldValue);
            }
        }

        s.close();
        baos.close();
        ByteBuffer outByteBuffer = ByteBuffer.wrap(baos.toByteArray());
        results.put("outByteBuffer", outByteBuffer);
    } catch (DocumentException | IOException | GeneralException e) {
        Debug.logError(e, module);
        results = ServiceUtil.returnError(e.getMessage());
    }
    return results;
}
 

/**
 * Use iText <code>{@link PdfStamper}</code> to stamp information from <code>{@link CashReceiptDocument}</code> into field
 * values on a PDF Form Template.
 *
 * @param document The cash receipt document the values will be pulled from.
 * @param searchPath The directory path of the template to be used to generate the cover sheet.
 * @param returnStream The output stream the cover sheet will be written to.
 */
protected void stampPdfFormValues(CashReceiptDocument document, String searchPath, OutputStream returnStream) throws Exception {
    String templateName = CR_COVERSHEET_TEMPLATE_NM;

    try {
        // populate form with document values

        //KFSMI-7303
        //The PDF template is retrieved through web static URL rather than file path, so the File separator is unnecessary
        final boolean isWebResourcePath = StringUtils.containsIgnoreCase(searchPath, "HTTP");

        //skip the File.separator if reference by web resource
        PdfStamper stamper = new PdfStamper(new PdfReader(searchPath + (isWebResourcePath? "" : File.separator) + templateName), returnStream);
        AcroFields populatedCoverSheet = stamper.getAcroFields();

        populatedCoverSheet.setField(DOCUMENT_NUMBER_FIELD, document.getDocumentNumber());
        populatedCoverSheet.setField(INITIATOR_FIELD, document.getDocumentHeader().getWorkflowDocument().getInitiatorPrincipalId());
        populatedCoverSheet.setField(CREATED_DATE_FIELD, document.getDocumentHeader().getWorkflowDocument().getDateCreated().toString());
        populatedCoverSheet.setField(AMOUNT_FIELD, document.getTotalDollarAmount().toString());
        populatedCoverSheet.setField(ORG_DOC_NUMBER_FIELD, document.getDocumentHeader().getOrganizationDocumentNumber());
        populatedCoverSheet.setField(CAMPUS_FIELD, document.getCampusLocationCode());

        if (document.getDepositDate() != null) {
            // This value won't be set until the CR document is
            // deposited. A CR document is deposited only when it has
            // been associated with a Cash Management Document (CMD)
            // and with a Deposit within that CMD. And only when the
            // CMD is submitted and FINAL, will the CR documents
            // associated with it, be "deposited." So this value will
            // fill in at an arbitrarily later point in time. So your
            // code shouldn't expect it, but if it's there, then
            // display it.
            populatedCoverSheet.setField(DEPOSIT_DATE_FIELD, document.getDepositDate().toString());
        }
        populatedCoverSheet.setField(DESCRIPTION_FIELD, document.getDocumentHeader().getDocumentDescription());
        populatedCoverSheet.setField(EXPLANATION_FIELD, document.getDocumentHeader().getExplanation());

        /*
         * We should print original amounts before cash manager approves the CR; after that, we should print confirmed amounts.
         * Note that, in CashReceiptAction.printCoverSheet, it always retrieves the CR from DB, rather than from the current form.
         * Since during CashManagement route node, the CR can't be saved until CM approves/disapproves the document; this means
         * that if CM prints during this route node, he will get the original amounts. This is consistent with our logic here.
         */
        boolean isConfirmed = document.isConfirmed();
        KualiDecimal totalCheckAmount = !isConfirmed ? document.getTotalCheckAmount() : document.getTotalConfirmedCheckAmount();
        KualiDecimal totalCurrencyAmount = !isConfirmed ? document.getTotalCurrencyAmount() : document.getTotalConfirmedCurrencyAmount();
        KualiDecimal totalCoinAmount = !isConfirmed ? document.getTotalCoinAmount() : document.getTotalConfirmedCoinAmount();
        KualiDecimal totalCashInAmount = !isConfirmed ? document.getTotalCashInAmount() : document.getTotalConfirmedCashInAmount();
        KualiDecimal totalMoneyInAmount = !isConfirmed ? document.getTotalMoneyInAmount() : document.getTotalConfirmedMoneyInAmount();
        KualiDecimal totalChangeCurrencyAmount = !isConfirmed ? document.getTotalChangeCurrencyAmount() : document.getTotalConfirmedChangeCurrencyAmount();
        KualiDecimal totalChangeCoinAmount = !isConfirmed ? document.getTotalChangeCoinAmount() : document.getTotalConfirmedChangeCoinAmount();
        KualiDecimal totalChangeAmount = !isConfirmed ? document.getTotalChangeAmount() : document.getTotalConfirmedChangeAmount();
        KualiDecimal totalNetAmount = !isConfirmed ? document.getTotalNetAmount() : document.getTotalConfirmedNetAmount();

        populatedCoverSheet.setField(CHECKS_FIELD, totalCheckAmount.toString());
        populatedCoverSheet.setField(CURRENCY_FIELD, totalCurrencyAmount.toString());
        populatedCoverSheet.setField(COIN_FIELD, totalCoinAmount.toString());
        populatedCoverSheet.setField(CASH_IN_FIELD, totalCashInAmount.toString());
        populatedCoverSheet.setField(MONEY_IN_FIELD, totalMoneyInAmount.toString());
        populatedCoverSheet.setField(CHANGE_CURRENCY_FIELD, totalChangeCurrencyAmount.toString());
        populatedCoverSheet.setField(CHANGE_COIN_FIELD, totalChangeCoinAmount.toString());
        populatedCoverSheet.setField(CHANGE_OUT_FIELD, totalChangeAmount.toString());
        populatedCoverSheet.setField(RECONCILIATION_TOTAL_FIELD, totalNetAmount.toString());

        stamper.setFormFlattening(true);
        stamper.close();
    }
    catch (Exception e) {
        LOG.error("Error creating coversheet for: " + document.getDocumentNumber() + ". ::" + e);
        throw e;
    }
}
 

/**
    * Reads the pages of an existing PDF file, adds pagenumbers and a watermark.

    */
@Test
   public  void main() throws Exception {
           // we create a reader for a certain document
           PdfReader reader = new PdfReader(PdfTestBase.RESOURCES_DIR +"ChapterSection.pdf");
           int n = reader.getNumberOfPages();
           // we create a stamper that will copy the document to a new file
           PdfStamper stamp = new PdfStamper(reader,PdfTestBase.getOutputStream("watermark_pagenumbers.pdf"));
           // adding some metadata
           HashMap<String, String> moreInfo = new HashMap<String, String>();
           moreInfo.put("Author", "Bruno Lowagie");
           stamp.setMoreInfo(moreInfo);
           // adding content to each page
           int i = 0;
           PdfContentByte under;
           PdfContentByte over;
           Image img = Image.getInstance(PdfTestBase.RESOURCES_DIR +"watermark.jpg");
           BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.WINANSI, BaseFont.EMBEDDED);
           img.setAbsolutePosition(200, 400);
           while (i < n) {
           	i++;
           	// watermark under the existing page
           	under = stamp.getUnderContent(i);
           	under.addImage(img);
           	// text over the existing page
           	over = stamp.getOverContent(i);
           	over.beginText();
           	over.setFontAndSize(bf, 18);
           	over.setTextMatrix(30, 30);
           	over.showText("page " + i);
           	over.setFontAndSize(bf, 32);
           	over.showTextAligned(Element.ALIGN_LEFT, "DUPLICATE", 230, 430, 45);
           	over.endText();
           }
           // adding an extra page
           stamp.insertPage(1, PageSize.A4);
           over = stamp.getOverContent(1);
       	over.beginText();
       	over.setFontAndSize(bf, 18);
           over.showTextAligned(Element.ALIGN_LEFT, "DUPLICATE OF AN EXISTING PDF DOCUMENT", 30, 600, 0);
           over.endText();
           // adding a page from another document
           PdfReader reader2 = new PdfReader(PdfTestBase.RESOURCES_DIR +"SimpleAnnotations1.pdf");
           under = stamp.getUnderContent(1);
           under.addTemplate(stamp.getImportedPage(reader2, 3), 1, 0, 0, 1, 0, 0);
           // closing PdfStamper will generate the new PDF file
           stamp.close();
   }
 

/**
 * Subclasses must implement this method to merge the PDF form
 * with the given model data.
 * <p>This is where you are able to set values on the AcroForm.
 * An example of what can be done at this level is:
 * <pre class="code">
 * // get the form from the document
 * AcroFields form = stamper.getAcroFields();
 *
 * // set some values on the form
 * form.setField("field1", "value1");
 * form.setField("field2", "Vvlue2");
 *
 * // set the disposition and filename
 * response.setHeader("Content-disposition", "attachment; FILENAME=someName.pdf");</pre>
 * <p>Note that the passed-in HTTP response is just supposed to be used
 * for setting cookies or other HTTP headers. The built PDF document itself
 * will automatically get written to the response after this method returns.
 * @param model the model Map
 * @param stamper the PdfStamper instance that will contain the AcroFields.
 * You may also customize this PdfStamper instance according to your needs,
 * e.g. setting the "formFlattening" property.
 * @param request in case we need locale etc. Shouldn't look at attributes.
 * @param response in case we need to set cookies. Shouldn't write to it.
 * @throws Exception any exception that occurred during document building
    */
protected abstract void mergePdfDocument(Map<String, Object> model, PdfStamper stamper,
		HttpServletRequest request, HttpServletResponse response) throws Exception;
 

/**
 * Subclasses must implement this method to merge the PDF form
 * with the given model data.
 * <p>This is where you are able to set values on the AcroForm.
 * An example of what can be done at this level is:
 * <pre class="code">
 * // get the form from the document
 * AcroFields form = stamper.getAcroFields();
 *
 * // set some values on the form
 * form.setField("field1", "value1");
 * form.setField("field2", "Vvlue2");
 *
 * // set the disposition and filename
 * response.setHeader("Content-disposition", "attachment; FILENAME=someName.pdf");</pre>
 * <p>Note that the passed-in HTTP response is just supposed to be used
 * for setting cookies or other HTTP headers. The built PDF document itself
 * will automatically get written to the response after this method returns.
 * @param model the model Map
 * @param stamper the PdfStamper instance that will contain the AcroFields.
 * You may also customize this PdfStamper instance according to your needs,
 * e.g. setting the "formFlattening" property.
 * @param request in case we need locale etc. Shouldn't look at attributes.
 * @param response in case we need to set cookies. Shouldn't write to it.
 * @throws Exception any exception that occurred during document building
    */
protected abstract void mergePdfDocument(Map<String, Object> model, PdfStamper stamper,
		HttpServletRequest request, HttpServletResponse response) throws Exception;
 

/**
 * Subclasses must implement this method to merge the PDF form
 * with the given model data.
 * <p>This is where you are able to set values on the AcroForm.
 * An example of what can be done at this level is:
 * <pre class="code">
 * // get the form from the document
 * AcroFields form = stamper.getAcroFields();
 *
 * // set some values on the form
 * form.setField("field1", "value1");
 * form.setField("field2", "Vvlue2");
 *
 * // set the disposition and filename
 * response.setHeader("Content-disposition", "attachment; FILENAME=someName.pdf");</pre>
 * <p>Note that the passed-in HTTP response is just supposed to be used
 * for setting cookies or other HTTP headers. The built PDF document itself
 * will automatically get written to the response after this method returns.
 * @param model the model Map
 * @param stamper the PdfStamper instance that will contain the AcroFields.
 * You may also customize this PdfStamper instance according to your needs,
 * e.g. setting the "formFlattening" property.
 * @param request in case we need locale etc. Shouldn't look at attributes.
 * @param response in case we need to set cookies. Shouldn't write to it.
 * @throws Exception any exception that occurred during document building
    */
protected abstract void mergePdfDocument(Map<String, Object> model, PdfStamper stamper,
		HttpServletRequest request, HttpServletResponse response) throws Exception;
 

/**
 * Subclasses must implement this method to merge the PDF form
 * with the given model data.
 * <p>This is where you are able to set values on the AcroForm.
 * An example of what can be done at this level is:
 * <pre class="code">
 * // get the form from the document
 * AcroFields form = stamper.getAcroFields();
 *
 * // set some values on the form
 * form.setField("field1", "value1");
 * form.setField("field2", "Vvlue2");
 *
 * // set the disposition and filename
 * response.setHeader("Content-disposition", "attachment; FILENAME=someName.pdf");</pre>
 * <p>Note that the passed-in HTTP response is just supposed to be used
 * for setting cookies or other HTTP headers. The built PDF document itself
 * will automatically get written to the response after this method returns.
 * @param model the model Map
 * @param stamper the PdfStamper instance that will contain the AcroFields.
 * You may also customize this PdfStamper instance according to your needs,
 * e.g. setting the "formFlattening" property.
 * @param request in case we need locale etc. Shouldn't look at attributes.
 * @param response in case we need to set cookies. Shouldn't write to it.
 * @throws Exception any exception that occurred during document building
    */
protected abstract void mergePdfDocument(Map<String, Object> model, PdfStamper stamper,
		HttpServletRequest request, HttpServletResponse response) throws Exception;