Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.pdfbox.pdmodel.interactive.digitalsignature.visible; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.nio.charset.StandardCharsets; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.pdfbox.cos.COSArray; import org.apache.pdfbox.cos.COSDictionary; import org.apache.pdfbox.cos.COSName; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.PDPage; import org.apache.pdfbox.pdmodel.PDResources; import org.apache.pdfbox.pdmodel.common.PDRectangle; import org.apache.pdfbox.pdmodel.common.PDStream; import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject; import org.apache.pdfbox.pdmodel.graphics.image.LosslessFactory; import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject; import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationWidget; import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceDictionary; import org.apache.pdfbox.pdmodel.interactive.annotation.PDAppearanceStream; import org.apache.pdfbox.pdmodel.interactive.digitalsignature.PDSignature; import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm; import org.apache.pdfbox.pdmodel.interactive.form.PDField; import org.apache.pdfbox.pdmodel.interactive.form.PDSignatureField; /** * Implementation of {@link PDFTemplateBuilder}. This builds the signature PDF but doesn't keep the * elements, these are kept in its PDF template structure. * * @author Vakhtang Koroghlishvili */ public class PDVisibleSigBuilder implements PDFTemplateBuilder { private final PDFTemplateStructure pdfStructure; private static final Log LOG = LogFactory.getLog(PDVisibleSigBuilder.class); /** * Constructor, creates PDF template structure. */ public PDVisibleSigBuilder() { pdfStructure = new PDFTemplateStructure(); LOG.info("PDF Structure has been created"); } @Override public void createPage(PDVisibleSignDesigner properties) { PDPage page = new PDPage(new PDRectangle(properties.getPageWidth(), properties.getPageHeight())); pdfStructure.setPage(page); LOG.info("PDF page has been created"); } /** * Creates a PDDocument and adds the page parameter to it and keeps this as a template in the * PDF template Structure. * * @param page * @throws IOException */ @Override public void createTemplate(PDPage page) throws IOException { PDDocument template = new PDDocument(); template.addPage(page); pdfStructure.setTemplate(template); } @Override public void createAcroForm(PDDocument template) { PDAcroForm theAcroForm = new PDAcroForm(template); template.getDocumentCatalog().setAcroForm(theAcroForm); pdfStructure.setAcroForm(theAcroForm); LOG.info("AcroForm has been created"); } @Override public PDFTemplateStructure getStructure() { return pdfStructure; } @Override public void createSignatureField(PDAcroForm acroForm) throws IOException { PDSignatureField sf = new PDSignatureField(acroForm); pdfStructure.setSignatureField(sf); LOG.info("Signature field has been created"); } @Override public void createSignature(PDSignatureField pdSignatureField, PDPage page, String signerName) throws IOException { PDSignature pdSignature = new PDSignature(); PDAnnotationWidget widget = pdSignatureField.getWidgets().get(0); pdSignatureField.setValue(pdSignature); widget.setPage(page); page.getAnnotations().add(widget); if (!signerName.isEmpty()) { pdSignature.setName(signerName); } pdfStructure.setPdSignature(pdSignature); LOG.info("PDSignature has been created"); } @Override public void createAcroFormDictionary(PDAcroForm acroForm, PDSignatureField signatureField) throws IOException { @SuppressWarnings("unchecked") List<PDField> acroFormFields = acroForm.getFields(); COSDictionary acroFormDict = acroForm.getCOSObject(); acroForm.setSignaturesExist(true); acroForm.setAppendOnly(true); acroFormDict.setDirect(true); acroFormFields.add(signatureField); // WTF sylfaen? acroForm.setDefaultAppearance("/sylfaen 0 Tf 0 g"); pdfStructure.setAcroFormFields(acroFormFields); pdfStructure.setAcroFormDictionary(acroFormDict); LOG.info("AcroForm dictionary has been created"); } @Override public void createSignatureRectangle(PDSignatureField signatureField, PDVisibleSignDesigner properties) throws IOException { PDRectangle rect = new PDRectangle(); rect.setUpperRightX(properties.getxAxis() + properties.getWidth()); rect.setUpperRightY(properties.getTemplateHeight() - properties.getyAxis()); rect.setLowerLeftY(properties.getTemplateHeight() - properties.getyAxis() - properties.getHeight()); rect.setLowerLeftX(properties.getxAxis()); signatureField.getWidgets().get(0).setRectangle(rect); pdfStructure.setSignatureRectangle(rect); LOG.info("Signature rectangle has been created"); } @Override public void createAffineTransform(AffineTransform affineTransform) { pdfStructure.setAffineTransform(affineTransform); LOG.info("Matrix has been added"); } @Override public void createProcSetArray() { COSArray procSetArr = new COSArray(); procSetArr.add(COSName.getPDFName("PDF")); procSetArr.add(COSName.getPDFName("Text")); procSetArr.add(COSName.getPDFName("ImageB")); procSetArr.add(COSName.getPDFName("ImageC")); procSetArr.add(COSName.getPDFName("ImageI")); pdfStructure.setProcSet(procSetArr); LOG.info("ProcSet array has been created"); } @Override public void createSignatureImage(PDDocument template, BufferedImage image) throws IOException { pdfStructure.setImage(LosslessFactory.createFromImage(template, image)); LOG.info("Visible Signature Image has been created"); } @Override public void createFormatterRectangle(int[] params) { PDRectangle formatterRectangle = new PDRectangle(); formatterRectangle.setLowerLeftX(Math.min(params[0], params[2])); formatterRectangle.setLowerLeftY(Math.min(params[1], params[3])); formatterRectangle.setUpperRightX(Math.max(params[0], params[2])); formatterRectangle.setUpperRightY(Math.max(params[1], params[3])); pdfStructure.setFormatterRectangle(formatterRectangle); LOG.info("Formatter rectangle has been created"); } @Override public void createHolderFormStream(PDDocument template) { PDStream holderForm = new PDStream(template); pdfStructure.setHolderFormStream(holderForm); LOG.info("Holder form stream has been created"); } @Override public void createHolderFormResources() { PDResources holderFormResources = new PDResources(); pdfStructure.setHolderFormResources(holderFormResources); LOG.info("Holder form resources have been created"); } @Override public void createHolderForm(PDResources holderFormResources, PDStream holderFormStream, PDRectangle bbox) { PDFormXObject holderForm = new PDFormXObject(holderFormStream); holderForm.setResources(holderFormResources); holderForm.setBBox(bbox); holderForm.setFormType(1); pdfStructure.setHolderForm(holderForm); LOG.info("Holder form has been created"); } @Override public void createAppearanceDictionary(PDFormXObject holderForml, PDSignatureField signatureField) throws IOException { PDAppearanceDictionary appearance = new PDAppearanceDictionary(); appearance.getCOSObject().setDirect(true); PDAppearanceStream appearanceStream = new PDAppearanceStream(holderForml.getCOSObject()); appearance.setNormalAppearance(appearanceStream); signatureField.getWidgets().get(0).setAppearance(appearance); pdfStructure.setAppearanceDictionary(appearance); LOG.info("PDF appearance dictionary has been created"); } @Override public void createInnerFormStream(PDDocument template) { PDStream innerFormStream = new PDStream(template); pdfStructure.setInnterFormStream(innerFormStream); LOG.info("Stream of another form (inner form - it will be inside holder form) " + "has been created"); } @Override public void createInnerFormResource() { PDResources innerFormResources = new PDResources(); pdfStructure.setInnerFormResources(innerFormResources); LOG.info("Resources of another form (inner form - it will be inside holder form)" + "have been created"); } @Override public void createInnerForm(PDResources innerFormResources, PDStream innerFormStream, PDRectangle bbox) { PDFormXObject innerForm = new PDFormXObject(innerFormStream); innerForm.setResources(innerFormResources); innerForm.setBBox(bbox); innerForm.setFormType(1); pdfStructure.setInnerForm(innerForm); LOG.info("Another form (inner form - it will be inside holder form) has been created"); } @Override public void insertInnerFormToHolderResources(PDFormXObject innerForm, PDResources holderFormResources) { holderFormResources.put(COSName.FRM, innerForm); pdfStructure.setInnerFormName(COSName.FRM); LOG.info("Now inserted inner form inside holder form"); } @Override public void createImageFormStream(PDDocument template) { PDStream imageFormStream = new PDStream(template); pdfStructure.setImageFormStream(imageFormStream); LOG.info("Created image form stream"); } @Override public void createImageFormResources() { PDResources imageFormResources = new PDResources(); pdfStructure.setImageFormResources(imageFormResources); LOG.info("Created image form resources"); } @Override public void createImageForm(PDResources imageFormResources, PDResources innerFormResource, PDStream imageFormStream, PDRectangle bbox, AffineTransform at, PDImageXObject img) throws IOException { PDFormXObject imageForm = new PDFormXObject(imageFormStream); imageForm.setBBox(bbox); imageForm.setMatrix(at); imageForm.setResources(imageFormResources); imageForm.setFormType(1); imageFormResources.getCOSObject().setDirect(true); COSName imageFormName = COSName.getPDFName("n2"); innerFormResource.put(imageFormName, imageForm); COSName imageName = imageFormResources.add(img, "img"); pdfStructure.setImageForm(imageForm); pdfStructure.setImageFormName(imageFormName); pdfStructure.setImageName(imageName); LOG.info("Created image form"); } @Override public void createBackgroundLayerForm(PDResources innerFormResource, PDRectangle bbox) throws IOException { // create blank n0 background layer form PDFormXObject n0Form = new PDFormXObject(pdfStructure.getTemplate().getDocument().createCOSStream()); n0Form.setBBox(bbox); n0Form.setResources(new PDResources()); n0Form.setFormType(1); innerFormResource.put(COSName.getPDFName("n0"), n0Form); LOG.info("Created background layer form"); } @Override public void injectProcSetArray(PDFormXObject innerForm, PDPage page, PDResources innerFormResources, PDResources imageFormResources, PDResources holderFormResources, COSArray procSet) { innerForm.getResources().getCOSObject().setItem(COSName.PROC_SET, procSet); page.getCOSObject().setItem(COSName.PROC_SET, procSet); innerFormResources.getCOSObject().setItem(COSName.PROC_SET, procSet); imageFormResources.getCOSObject().setItem(COSName.PROC_SET, procSet); holderFormResources.getCOSObject().setItem(COSName.PROC_SET, procSet); LOG.info("Inserted ProcSet to PDF"); } @Override public void injectAppearanceStreams(PDStream holderFormStream, PDStream innerFormStream, PDStream imageFormStream, COSName imageFormName, COSName imageName, COSName innerFormName, PDVisibleSignDesigner properties) throws IOException { // Use width and height of BBox as values for transformation matrix. int width = (int) this.getStructure().getFormatterRectangle().getWidth(); int height = (int) this.getStructure().getFormatterRectangle().getHeight(); String imgFormContent = "q " + width + " 0 0 " + height + " 0 0 cm /" + imageName.getName() + " Do Q\n"; String holderFormContent = "q 1 0 0 1 0 0 cm /" + innerFormName.getName() + " Do Q\n"; String innerFormContent = "q 1 0 0 1 0 0 cm /n0 Do Q q 1 0 0 1 0 0 cm /" + imageFormName.getName() + " Do Q\n"; appendRawCommands(pdfStructure.getHolderFormStream().createOutputStream(), holderFormContent); appendRawCommands(pdfStructure.getInnerFormStream().createOutputStream(), innerFormContent); appendRawCommands(pdfStructure.getImageFormStream().createOutputStream(), imgFormContent); LOG.info("Injected appearance stream to pdf"); } public void appendRawCommands(OutputStream os, String commands) throws IOException { os.write(commands.getBytes(StandardCharsets.UTF_8)); os.close(); } @Override public void createVisualSignature(PDDocument template) { pdfStructure.setVisualSignature(template.getDocument()); LOG.info("Visible signature has been created"); } @Override public void createWidgetDictionary(PDSignatureField signatureField, PDResources holderFormResources) throws IOException { COSDictionary widgetDict = signatureField.getWidgets().get(0).getCOSObject(); widgetDict.setNeedToBeUpdated(true); widgetDict.setItem(COSName.DR, holderFormResources.getCOSObject()); pdfStructure.setWidgetDictionary(widgetDict); LOG.info("WidgetDictionary has been created"); } @Override public void closeTemplate(PDDocument template) throws IOException { template.close(); pdfStructure.getTemplate().close(); } }