Java tutorial
/******************************************************************************* * Copyright 2010 Atos Worldline SAS * * Licensed by Atos Worldline SAS under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * Atos Worldline SAS 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 net.padaf.preflight.graphics; import java.util.ArrayList; import java.util.List; import net.padaf.preflight.DocumentHandler; import net.padaf.preflight.ValidationConstants; import net.padaf.preflight.ValidationException; import net.padaf.preflight.ValidationResult.ValidationError; import net.padaf.preflight.utils.COSUtils; import org.apache.pdfbox.cos.COSBase; import org.apache.pdfbox.cos.COSDocument; import org.apache.pdfbox.cos.COSName; import org.apache.pdfbox.cos.COSStream; import static net.padaf.preflight.ValidationConstants.*; /** * This class processes commons validations of XObjects. */ public abstract class AbstractXObjValidator implements XObjectValidator { /** * The XObject to validate as a COSStream. */ protected COSStream xobject = null; /** * The document handler which contains useful information to process * validation. */ protected DocumentHandler handler = null; /** * The PDF document as COSDocument. */ protected COSDocument cosDocument = null; public AbstractXObjValidator(DocumentHandler handler, COSStream xobj) { this.xobject = xobj; this.handler = handler; this.cosDocument = handler.getDocument().getDocument(); } /** * This method checks the SMask entry in the XObject dictionary. According to * the PDF Reference, a SMask in a XObject is a Stream. So if it is not null, * it should be an error but a SMask with the name None is authorized in the * PDF/A Specification 6.4. If the validation fails (SMask not null and * different from None), the error list is updated with the error code * ERROR_GRAPHIC_TRANSPARENCY_SMASK (2.2.2). * * @param error * the list of error to update if the validation fails * @return true if the SMask is valid, false otherwise. */ protected boolean checkSMask(List<ValidationError> error) { COSBase smask = xobject.getItem(COSName.getPDFName(TRANSPARENCY_DICTIONARY_KEY_SOFT_MASK)); // if (smask != null && !(COSUtils.isString(smask, cosDocument) && TRANSPARENCY_DICTIONARY_VALUE_SOFT_MASK_NONE.equals(COSUtils.getAsString(smask, cosDocument)))) { error.add(new ValidationError(ERROR_GRAPHIC_TRANSPARENCY_SMASK, "Soft Mask must be null or None")); return false; } return true; } /** * According the ISO 190005:1-2005 specification, a XObject can't have an OPI * entry in its dictionary. If the XObject has a OPI entry, the error list is * updated with the error code ERROR_GRAPHIC_UNEXPECTED_KEY (2.3). * * @param errors * the list of error to update if the validation fails. * @return true if the OPI is missing, false otherwise. */ protected boolean checkOPI(List<ValidationError> errors) { // 6.2.4 and 6.2.5 no OPI if (this.xobject.getItem(COSName.getPDFName("OPI")) != null) { errors.add( new ValidationError(ValidationConstants.ERROR_GRAPHIC_UNEXPECTED_KEY, "Unexpected 'OPI' Key")); return false; } return true; } /** * According the ISO 190005:1-2005 specification, a XObject can't have an Ref * entry in its dictionary. If the XObject has a Ref entry, the error list is * updated with the error code ERROR_GRAPHIC_UNEXPECTED_KEY (2.3). * * @param errors * the list of error to update if the validation fails. * @return true if the Ref is missing, false otherwise. */ protected boolean checkReferenceXObject(List<ValidationError> errors) { // 6.2.6 No reference xobject if (this.xobject.getItem(COSName.getPDFName("Ref")) != null) { errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_KEY, "No reference Xobject allowed in PDF/A")); return false; } return true; } /** * According the ISO 190005:1-2005 specification, PostSCript XObject are * forbidden. If the XObject is a PostScript XObject, the error list is * updated with the error code ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY (2.3.2). * * To know the if the object a Postscript XObject, "Subtype" and "Subtype2" * entries are checked. * * @param errors * the list of error to update if the validation fails. * @return true if the XObject isn't a Postscript XObject, false otherwise. */ protected boolean checkPostscriptXObject(List<ValidationError> errors) { // 6.2.7 No PostScript XObjects if (this.xobject.getItem(COSName.SUBTYPE) != null && XOBJECT_DICTIONARY_VALUE_SUBTYPE_POSTSCRIPT .equals(this.xobject.getNameAsString(COSName.SUBTYPE))) { errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY, "No Postscript Xobject allowed in PDF/A")); return false; } if (this.xobject.getItem(COSName.getPDFName("Subtype2")) != null) { errors.add(new ValidationError(ERROR_GRAPHIC_UNEXPECTED_VALUE_FOR_KEY, "No Postscript Xobject allowed in PDF/A (Subtype2)")); return false; } return true; } /** * This method checks if required fields are present. * * @param result * the list of error to update if the validation fails. * @return true if all fields are present, false otherwise. */ protected abstract boolean checkMandatoryFields(List<ValidationError> result); /* * (non-Javadoc) * * @see net.awl.edoc.pdfa.validation.graphics.XObjectValidator#validate() */ public List<ValidationError> validate() throws ValidationException { List<ValidationError> result = new ArrayList<ValidationError>(0); if (checkMandatoryFields(result)) { checkOPI(result); checkSMask(result); checkReferenceXObject(result); checkPostscriptXObject(result); } return result; } }