Reworked the API of the ZUGFeRDExporter: Extract factory for PDF/A1 & PDF/A3 conversion, removed JAXB exceptions from public API, use enums as configuration constants, improved exception handling

mustang/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDConformanceLevel.java

@@ -0,0 +1,5 @@
+package org.mustangproject.ZUGFeRD;
+
+public enum ZUGFeRDConformanceLevel {
+    BASIC, COMFORT, EXTENDED
+}

mustang/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExportException.java

@@ -0,0 +1,18 @@
+package org.mustangproject.ZUGFeRD;
+
+public class ZUGFeRDExportException extends RuntimeException {
+    public ZUGFeRDExportException() {
+    }
+
+    public ZUGFeRDExportException(String message) {
+        super(message);
+    }
+
+    public ZUGFeRDExportException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ZUGFeRDExportException(Throwable cause) {
+        super(cause);
+    }
+}

mustang/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporter.java

@@ -26,10 +26,7 @@ import java.util.GregorianCalendar;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
-import javax.activation.FileDataSource;
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBElement;
 import javax.xml.bind.JAXBException;
@@ -37,30 +34,16 @@ import javax.xml.bind.Marshaller;
 import javax.xml.transform.TransformerException;
 
 
-import org.apache.xmpbox.XMPMetadata;
-import org.apache.xmpbox.schema.XMPBasicSchema;
-import org.apache.xmpbox.schema.DublinCoreSchema;
-import org.apache.xmpbox.schema.AdobePDFSchema;
-import org.apache.xmpbox.schema.PDFAIdentificationSchema;
 import org.apache.pdfbox.cos.COSArray;
 import org.apache.pdfbox.cos.COSBase;
 import org.apache.pdfbox.cos.COSDictionary;
 import org.apache.pdfbox.cos.COSName;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
-import org.apache.pdfbox.pdmodel.PDDocumentInformation;
 import org.apache.pdfbox.pdmodel.PDDocumentNameDictionary;
 import org.apache.pdfbox.pdmodel.PDEmbeddedFilesNameTreeNode;
-import org.apache.pdfbox.pdmodel.common.PDMetadata;
 import org.apache.pdfbox.pdmodel.common.filespecification.PDComplexFileSpecification;
 import org.apache.pdfbox.pdmodel.common.filespecification.PDEmbeddedFile;
-import org.apache.pdfbox.preflight.PreflightDocument;
-import org.apache.pdfbox.preflight.ValidationResult;
-import org.apache.pdfbox.preflight.exception.ValidationException;
-import org.apache.pdfbox.preflight.parser.PreflightParser;
-import org.apache.pdfbox.preflight.utils.ByteArrayDataSource;
-import org.apache.xmpbox.type.BadFieldValueException;
-import org.apache.xmpbox.xml.XmpSerializer;
 import org.mustangproject.ZUGFeRD.model.*;
 
 public class ZUGFeRDExporter implements Closeable {
@@ -78,15 +61,26 @@ public class ZUGFeRDExporter implements Closeable {
 	 * doc.save(PDFfilename);
 	 *
 	 * @author jstaerk
-	 * @throws javax.xml.bind.JAXBException
+	 * @deprecated Use the factory methods {@link #createFromPDFA3(String)}, {@link #createFromPDFA3(InputStream)} or
+     *             the {@link ZUGFeRDExporterFromA1Factory} instead
 	 *
 	 */
-	public ZUGFeRDExporter() throws JAXBException {
+	@Deprecated
+	public ZUGFeRDExporter() {
+		this(null);
+	}
+
+	ZUGFeRDExporter(PDDocument doc) {
+		this.doc = doc;
+		try {
 			jaxbContext = JAXBContext
 				.newInstance("org.mustangproject.ZUGFeRD.model");
 			marshaller = jaxbContext.createMarshaller();
 			marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
 			marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
+		} catch (JAXBException e) {
+			throw new ZUGFeRDExportException("Could not initialize JAXB", e);
+		}
 	}
 
 	private class LineCalc {
@@ -222,11 +216,12 @@ public class ZUGFeRDExporter implements Closeable {
 	}
 
 	// // MAIN CLASS
+	@Deprecated
 	private String conformanceLevel = "U";
-	private String versionStr = "1.4.0";
 
 	// BASIC, COMFORT etc - may be set from outside.
-	private String ZUGFeRDConformanceLevel = null;
+	@Deprecated
+	private String zugferdConformanceLevel = "EXTENDED";
 
 	/**
 	 * Data (XML invoice) to be added to the ZUGFeRD PDF. It may be externally
@@ -237,6 +232,7 @@ public class ZUGFeRDExporter implements Closeable {
 	byte[] zugferdData = null;
 	private boolean isTest;
 	IZUGFeRDExportableTransaction trans = null;
+	@Deprecated
 	private boolean ignoreA1Errors;
 	private PDDocument doc;
 	private String currency = "EUR";
@@ -315,6 +311,7 @@ public class ZUGFeRDExporter implements Closeable {
 	 *
 	 *
 	 */
+	@Deprecated
 	public void setConformanceLevel(String newLevel) {
 		conformanceLevel = newLevel;
 	}
@@ -327,84 +324,15 @@ public class ZUGFeRDExporter implements Closeable {
 		isTest = true;
 	}
 
+	@Deprecated
 	public void ignoreA1Errors() {
 		ignoreA1Errors = true;
 	}
 
-	private boolean getA1ParserValidationResult(PreflightParser parser) {
+    /**
-		ValidationResult result = null;
+     * @deprecated Use the factory method {@link #createFromPDFA3(String)} instead
-
-		try {
-
-			/*
-			 * Parse the PDF file with PreflightParser that inherits from the
-			 * NonSequentialParser. Some additional controls are present to
-			 * check a set of PDF/A requirements. (Stream length consistency,
-			 * EOL after some Keyword...)
      */
-			parser.parse();
+	@Deprecated
-
-			/*
-			 * Once the syntax validation is done, the parser can provide a
-			 * PreflightDocument (that inherits from PDDocument) This document
-			 * process the end of PDF/A validation.
-			 */
-			PreflightDocument document = parser.getPreflightDocument();
-			document.validate();
-
-			// Get validation result
-			result = document.getResult();
-			document.close();
-
-		} catch (ValidationException e) {
-			/*
-			 * the parse method can throw a SyntaxValidationException if the PDF
-			 * file can't be parsed. In this case, the exception contains an
-			 * instance of ValidationResult
-			 */
-			return false;
-		} catch (IOException e) {
-			return false;
-		}
-
-		// display validation result
-		return result.isValid();
-
-	}
-
-	public boolean isValidA1(String filename) {
-		FileDataSource fd = new FileDataSource(filename);
-		PreflightParser parser;
-		try {
-			parser = new PreflightParser(fd);
-		} catch (IOException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-			return false;
-		}
-
-		return getA1ParserValidationResult(parser);
-	}
-
-	/***
-	 * Will return a boolean if the inputstream is valid PDF/A-1 and close the input stream
-	 * @param file
-	 * @return
-	 */
-	public boolean isValidA1(InputStream file) {
-		
-            ByteArrayDataSource fd;
-            try {
-                    fd = new ByteArrayDataSource(file);
-                    PreflightParser parser = new PreflightParser(fd);
-                    return getA1ParserValidationResult(parser);
-            } catch (IOException e) {
-                    // TODO Auto-generated catch block
-                    e.printStackTrace();
-                    return false;
-            }
-        }
-
 	public void loadPDFA3(String filename) {
 
 		try {
@@ -418,6 +346,14 @@ public class ZUGFeRDExporter implements Closeable {
 
 	}
 
+	public static ZUGFeRDExporter createFromPDFA3(String filename) throws IOException {
+		return new ZUGFeRDExporter(PDDocument.load(new File(filename)));
+	}
+
+    /**
+     * @deprecated Use the factory method {@link #createFromPDFA3(InputStream)} instead
+     */
+	@Deprecated
 	public void loadPDFA3(InputStream file) {
 
 		try {
@@ -430,114 +366,57 @@ public class ZUGFeRDExporter implements Closeable {
 
 	}
 
+	public static ZUGFeRDExporter createFromPDFA3(InputStream pdfSource) throws IOException {
+		return new ZUGFeRDExporter(PDDocument.load(pdfSource));
+	}
+
 	/**
 	 * Makes A PDF/A3a-compliant document from a PDF-A1 compliant document (on
 	 * the metadata level, this will not e.g. convert graphics to JPG-2000)
      *
+     * @deprecated use the {@link ZUGFeRDExporterFromA1Factory} instead
+	 *
 	 */
+	@Deprecated
 	public PDDocumentCatalog PDFmakeA3compliant(String filename,
 												String producer, String creator, boolean attachZugferdHeaders)
 			throws IOException, TransformerException {
 
-		if (!ignoreA1Errors && !isValidA1(filename)) {
+		doc = createPDFA1Factory()
-			throw new IOException("File is not a valid PDF/A-1 input file");
+            .setProducer(producer)
-		}
+            .setCreator(creator)
-		loadPDFA3(filename);
+            .setAttachZugferdHeaders(attachZugferdHeaders)
+			.loadFromPDFA1(filename)
+			.doc;
 
-		return makeDocPDFA3compliant(producer, creator, attachZugferdHeaders);
+		return doc.getDocumentCatalog();
 	}
 
+	/**
+     * @deprecated use the {@link ZUGFeRDExporterFromA1Factory} instead
+     */
+	@Deprecated
 	public PDDocumentCatalog PDFmakeA3compliant(InputStream file,
-			String producer, String creator, boolean attachZugferdHeaders)
+			String producer, String creator, boolean attachZugferdHeaders) throws IOException, TransformerException {
-			throws IOException, TransformerException {
-		/* cache the file content in memory, unfortunately the next step, isValidA1,
-		 * will close the input stream but the step thereafter (loadPDFA3) needs
-		 * and open one*/
-		ByteArrayOutputStream baos = new ByteArrayOutputStream();
-		byte[] buf = new byte[1024];
-		int n = 0;
-		while ((n = file.read(buf)) >= 0)
-		    baos.write(buf, 0, n);
-		byte[] content = baos.toByteArray();
 
-		InputStream is1 = new ByteArrayInputStream(content);
+		doc = createPDFA1Factory()
-		if (!ignoreA1Errors && !isValidA1(is1)) {
+            .setProducer(producer)
-			throw new IOException("File is not a valid PDF/A-1 input file");
+            .setCreator(creator)
-		}
+            .setAttachZugferdHeaders(attachZugferdHeaders)
-		InputStream is2 = new ByteArrayInputStream(content);
+			.loadFromPDFA1(file)
-		loadPDFA3(is2);
+			.doc;
 
-		return makeDocPDFA3compliant(producer, creator, attachZugferdHeaders);
+		return doc.getDocumentCatalog();
-	}	
-	private PDDocumentCatalog makeDocPDFA3compliant(String producer,
-			String creator, boolean attachZugferdHeaders) throws IOException,
-			TransformerException {
-		String fullProducer = producer + " (via mustangproject.org "
-				+ versionStr + ")";
-
-		PDDocumentCatalog cat = doc.getDocumentCatalog();
-		PDMetadata metadata = new PDMetadata(doc);
-		cat.setMetadata(metadata);
-		XMPMetadata xmp = XMPMetadata.createXMPMetadata();
-
-                
-		PDFAIdentificationSchema pdfaid = new PDFAIdentificationSchema(xmp);
-                
-		xmp.addSchema(pdfaid);
-
-		DublinCoreSchema dc = xmp.createAndAddDublinCoreSchema();
-                
-		dc.addCreator(creator);
-                
-		XMPBasicSchema xsb = xmp.createAndAddXMPBasicSchema();
-                
-		xsb.setCreatorTool(creator);
-		xsb.setCreateDate(GregorianCalendar.getInstance());
-		// PDDocumentInformation pdi=doc.getDocumentInformation();
-		PDDocumentInformation pdi = new PDDocumentInformation();
-		pdi.setProducer(fullProducer);
-		pdi.setAuthor(creator);
-		doc.setDocumentInformation(pdi);
-
-		AdobePDFSchema pdf = xmp.createAndAddAdobePDFSchema();
-		pdf.setProducer(fullProducer);
-
-                /*
-                * // Mandatory: PDF/A3-a is tagged PDF which has to be expressed using
-                * a // MarkInfo dictionary (PDF A/3 Standard sec. 6.7.2.2) PDMarkInfo
-                * markinfo = new PDMarkInfo(); markinfo.setMarked(true);
-                * doc.getDocumentCatalog().setMarkInfo(markinfo);
-                */
-                /*
-                *
-                * To be on the safe side, we use level B without Markinfo because we
-                * can not guarantee that the user correctly tagged the templates for
-                * the PDF.
-                */
-                try {
-                    pdfaid.setConformance(conformanceLevel);//$NON-NLS-1$ //$NON-NLS-1$
-                } catch (BadFieldValueException ex) {
-                    Logger.getLogger(ZUGFeRDExporter.class.getName()).log(Level.SEVERE, null, ex);
 	}
 
-		pdfaid.setPart(3);
+	private ZUGFeRDExporterFromA1Factory createPDFA1Factory() {
-
+		ZUGFeRDExporterFromA1Factory factory = new ZUGFeRDExporterFromA1Factory();
-		if (attachZugferdHeaders) {
+		if (ignoreA1Errors) {
-			addZugferdXMP(xmp); /*
+			factory.ignoreA1Errors();
-								 * this is the only line where we do something
-								 * Zugferd-specific, i.e. add PDF metadata
-								 * specifically for Zugferd, not generically for
-								 * a embedded file
-								 */
-
 		}
-
+		return factory
-                XmpSerializer serializer = new XmpSerializer();
+			.setZugferdConformanceLevel(ZUGFeRDConformanceLevel.valueOf(zugferdConformanceLevel))
-                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+			.setConformanceLevel(PDFAConformanceLevel.valueOf(conformanceLevel));
-                serializer.serialize(xmp, baos, false);
-                metadata.importXMPMetadata( baos.toByteArray() );
-                
-		return cat;
 	}
 
 	public void close() throws IOException {
@@ -554,8 +433,15 @@ public class ZUGFeRDExporter implements Closeable {
 
 	private Totals totals;
 
-	private String getZugferdXMLForTransaction(
+	private String createZugferdXMLForTransaction(IZUGFeRDExportableTransaction trans) {
-			IZUGFeRDExportableTransaction trans) throws JAXBException {
+		try {
+			return tryCreateZugferdXMLForTransaction(trans);
+		} catch (JAXBException e) {
+			throw new ZUGFeRDExportException("Could not serialize transaction to XML", e);
+		}
+	}
+
+	private String tryCreateZugferdXMLForTransaction(IZUGFeRDExportableTransaction trans) throws JAXBException {
 		this.trans = trans;
 		this.totals = new Totals();
 		currency = trans.getCurrency();
@@ -1388,7 +1274,7 @@ public class ZUGFeRDExporter implements Closeable {
 	 *            <code>setZUGFeRDXMLData(byte[] zugferdData)</code>
 	 */
 	public void PDFattachZugferdFile(IZUGFeRDExportableTransaction trans)
-			throws IOException, JAXBException {
+			throws IOException {
 
             if (zugferdData == null) // XML ZUGFeRD data not set externally, needs
                                                                     // to be built
@@ -1396,7 +1282,7 @@ public class ZUGFeRDExporter implements Closeable {
                     // create a dummy file stream, this would probably normally be a
                     // FileInputStream
 
-                    byte[] zugferdRaw = getZugferdXMLForTransaction(trans).getBytes(); //$NON-NLS-1$
+                    byte[] zugferdRaw = createZugferdXMLForTransaction(trans).getBytes(); //$NON-NLS-1$
 
                     if ((zugferdRaw[0] == (byte) 0xEF)
                                     && (zugferdRaw[1] == (byte) 0xBB)
@@ -1526,29 +1412,12 @@ public class ZUGFeRDExporter implements Closeable {
 	 * @param ZUGFeRDConformanceLevel
 	 *            the new conformance level
 	 */
+	@Deprecated
 	public void setZUGFeRDConformanceLevel(String ZUGFeRDConformanceLevel) {
-		this.ZUGFeRDConformanceLevel = ZUGFeRDConformanceLevel;
+		this.zugferdConformanceLevel = ZUGFeRDConformanceLevel;
 	}
 
-	/**
-	 * * This will add both the RDF-indication which embedded file is Zugferd
-	 * and the neccessary PDF/A schema extension description to be able to add
-	 * this information to RDF
-	 *
-	 * @param metadata
-	 */
-	private void addZugferdXMP(XMPMetadata metadata) {
 
-		XMPSchemaZugferd zf = new XMPSchemaZugferd(metadata,
-				this.ZUGFeRDConformanceLevel);
-
-		metadata.addSchema(zf);
-
-		XMPSchemaPDFAExtensions pdfaex = new XMPSchemaPDFAExtensions(metadata);
-                
-		metadata.addSchema(pdfaex);
-
-	}
 
 	/****
 	 * Returns the PDFBox PDF Document

mustang/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDExporterFromA1Factory.java

@@ -0,0 +1,276 @@
+package org.mustangproject.ZUGFeRD;
+
+import org.apache.pdfbox.io.IOUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
+import org.apache.pdfbox.pdmodel.PDDocumentInformation;
+import org.apache.pdfbox.pdmodel.common.PDMetadata;
+import org.apache.pdfbox.preflight.PreflightDocument;
+import org.apache.pdfbox.preflight.exception.ValidationException;
+import org.apache.pdfbox.preflight.parser.PreflightParser;
+import org.apache.pdfbox.preflight.utils.ByteArrayDataSource;
+import org.apache.xmpbox.XMPMetadata;
+import org.apache.xmpbox.schema.AdobePDFSchema;
+import org.apache.xmpbox.schema.DublinCoreSchema;
+import org.apache.xmpbox.schema.PDFAIdentificationSchema;
+import org.apache.xmpbox.schema.XMPBasicSchema;
+import org.apache.xmpbox.type.BadFieldValueException;
+import org.apache.xmpbox.xml.XmpSerializer;
+import org.mustangproject.ZUGFeRD.model.PDFAConformanceLevel;
+
+import javax.activation.DataSource;
+import javax.activation.FileDataSource;
+import javax.xml.transform.TransformerException;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.GregorianCalendar;
+
+public class ZUGFeRDExporterFromA1Factory {
+    private static final String VERSION_STR = "1.4.0";
+
+    private boolean ignoreA1Errors = false;
+    private ZUGFeRDConformanceLevel zugferdConformanceLevel = ZUGFeRDConformanceLevel.EXTENDED;
+    private PDFAConformanceLevel conformanceLevel = PDFAConformanceLevel.U;
+    private String producer = "mustangproject";
+    private String creator = "mustangproject";
+    private boolean attachZugferdHeaders = true;
+
+    /**
+     * Makes A PDF/A3a-compliant document from a PDF-A1 compliant document (on
+     * the metadata level, this will not e.g. convert graphics to JPG-2000)
+     *
+     * @param pdfFilename filename of an PDF/A1 compliant document
+     */
+    public ZUGFeRDExporter loadFromPDFA1(String pdfFilename) throws IOException {
+        ensurePDFIsValidA1(new FileDataSource(pdfFilename));
+
+        PDDocument doc = PDDocument.load(new File(pdfFilename));
+        makePDFA3compliant(doc);
+        return new ZUGFeRDExporter(doc);
+    }
+
+    /**
+     * Makes A PDF/A3a-compliant document from a PDF-A1 compliant document (on
+     * the metadata level, this will not e.g. convert graphics to JPG-2000)
+     *
+     * @param pdfBinary binary of a PDF/A1 compliant document
+     */
+    public ZUGFeRDExporter loadFromPDFA1(byte[] pdfBinary) throws IOException, TransformerException {
+        ensurePDFIsValidA1(new ByteArrayDataSource(new ByteArrayInputStream(pdfBinary)));
+
+        PDDocument doc = PDDocument.load(pdfBinary);
+        makePDFA3compliant(doc);
+        return new ZUGFeRDExporter(doc);
+    }
+
+    /**
+     * Makes A PDF/A3a-compliant document from a PDF-A1 compliant document (on
+     * the metadata level, this will not e.g. convert graphics to JPG-2000)
+     *
+     * @param pdfSource source to read a PDF/A1 compliant document from
+     */
+    public ZUGFeRDExporter loadFromPDFA1(InputStream pdfSource) throws IOException, TransformerException {
+        return loadFromPDFA1(readAllBytes(pdfSource));
+    }
+
+    private void ensurePDFIsValidA1(final DataSource dataSource) throws IOException {
+        if (!ignoreA1Errors && !isValidA1(dataSource)) {
+            throw new IOException("File is not a valid PDF/A-1 input file");
+        }
+    }
+
+    private static byte[] readAllBytes(InputStream in) throws IOException {
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        IOUtils.copy(in, buffer);
+        return buffer.toByteArray();
+    }
+
+    private void makePDFA3compliant(PDDocument doc) throws IOException {
+        String fullProducer = producer + " (via mustangproject.org " + VERSION_STR + ")";
+
+        PDDocumentCatalog cat = doc.getDocumentCatalog();
+        PDMetadata metadata = new PDMetadata(doc);
+        cat.setMetadata(metadata);
+        XMPMetadata xmp = XMPMetadata.createXMPMetadata();
+
+
+        PDFAIdentificationSchema pdfaid = new PDFAIdentificationSchema(xmp);
+
+        xmp.addSchema(pdfaid);
+
+        DublinCoreSchema dc = xmp.createAndAddDublinCoreSchema();
+
+        dc.addCreator(creator);
+
+        XMPBasicSchema xsb = xmp.createAndAddXMPBasicSchema();
+
+        xsb.setCreatorTool(creator);
+        xsb.setCreateDate(GregorianCalendar.getInstance());
+        // PDDocumentInformation pdi=doc.getDocumentInformation();
+        PDDocumentInformation pdi = new PDDocumentInformation();
+        pdi.setProducer(fullProducer);
+        pdi.setAuthor(creator);
+        doc.setDocumentInformation(pdi);
+
+        AdobePDFSchema pdf = xmp.createAndAddAdobePDFSchema();
+        pdf.setProducer(fullProducer);
+
+        /*
+        * // Mandatory: PDF/A3-a is tagged PDF which has to be expressed using
+        * a // MarkInfo dictionary (PDF A/3 Standard sec. 6.7.2.2) PDMarkInfo
+        * markinfo = new PDMarkInfo(); markinfo.setMarked(true);
+        * doc.getDocumentCatalog().setMarkInfo(markinfo);
+        */
+        /*
+        *
+        * To be on the safe side, we use level B without Markinfo because we
+        * can not guarantee that the user correctly tagged the templates for
+        * the PDF.
+        */
+        try {
+            pdfaid.setConformance(conformanceLevel.getLetter());//$NON-NLS-1$ //$NON-NLS-1$
+        } catch (BadFieldValueException ex) {
+            // This should be impossible, because it would occur only if an illegal conformance level is supplied,
+            // however the enum enforces that the conformance level is valid.
+            throw new Error(ex);
+        }
+
+        pdfaid.setPart(3);
+
+        if (attachZugferdHeaders) {
+            addZugferdXMP(xmp); /*
+								 * this is the only line where we do something
+								 * Zugferd-specific, i.e. add PDF metadata
+								 * specifically for Zugferd, not generically for
+								 * a embedded file
+								 */
+
+        }
+
+
+        try {
+            metadata.importXMPMetadata(serializeXmpMetadata(xmp));
+        } catch (TransformerException e) {
+            throw new ZUGFeRDExportException("Could not export XmpMetadata", e);
+        }
+    }
+
+    private static byte[] serializeXmpMetadata(XMPMetadata xmpMetadata) throws TransformerException {
+        XmpSerializer serializer = new XmpSerializer();
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        serializer.serialize(xmpMetadata, buffer, false);
+        return buffer.toByteArray();
+    }
+
+    private static boolean isValidA1(DataSource dataSource) throws IOException {
+        return getA1ParserValidationResult(new PreflightParser(dataSource));
+    }
+
+    /**
+     * This will add both the RDF-indication which embedded file is Zugferd
+     * and the neccessary PDF/A schema extension description to be able to add
+     * this information to RDF
+     *
+     * @param metadata
+     */
+    private void addZugferdXMP(XMPMetadata metadata) {
+
+        XMPSchemaZugferd zf = new XMPSchemaZugferd(metadata, zugferdConformanceLevel.name());
+
+        metadata.addSchema(zf);
+
+        XMPSchemaPDFAExtensions pdfaex = new XMPSchemaPDFAExtensions(metadata);
+
+        metadata.addSchema(pdfaex);
+
+    }
+
+    /**
+     * Sets the ZUGFeRD conformance level (override).
+     *
+     * @param zugferdConformanceLevel
+     *            the new conformance level
+     */
+    public ZUGFeRDExporterFromA1Factory setZugferdConformanceLevel(ZUGFeRDConformanceLevel zugferdConformanceLevel) {
+        this.zugferdConformanceLevel = zugferdConformanceLevel;
+        return this;
+    }
+
+    private static boolean getA1ParserValidationResult(PreflightParser parser) throws IOException {
+        PreflightDocument document = null;
+        try {
+
+			/*
+			 * Parse the PDF file with PreflightParser that inherits from the
+			 * NonSequentialParser. Some additional controls are present to
+			 * check a set of PDF/A requirements. (Stream length consistency,
+			 * EOL after some Keyword...)
+			 */
+            parser.parse();
+
+			/*
+			 * Once the syntax validation is done, the parser can provide a
+			 * PreflightDocument (that inherits from PDDocument) This document
+			 * process the end of PDF/A validation.
+			 */
+            document = parser.getPreflightDocument();
+            document.validate();
+
+            // Get validation result
+            return document.getResult().isValid();
+        } catch (ValidationException e) {
+			/*
+			 * the parse method can throw a SyntaxValidationException if the PDF
+			 * file can't be parsed. In this case, the exception contains an
+			 * instance of ValidationResult
+			 */
+            return false;
+        } finally {
+            if (document != null) {
+                document.close();
+            }
+        }
+    }
+
+    /**
+     * All files are PDF/A-3, setConformance refers to the level conformance.
+     *
+     * PDF/A-3 has three coformance levels, called "A", "U" and "B".
+     *
+     * PDF/A-3-B where B means only visually preservable, U -standard for
+     * Mustang- means visually and unicode preservable and A means full
+     * compliance, i.e. visually, unicode and structurally preservable and
+     * tagged PDF, i.e. useful metainformation for blind people.
+     *
+     * Feel free to pass "A" as new level if you know what you are doing :-)
+     *
+     *
+     */
+    public ZUGFeRDExporterFromA1Factory setConformanceLevel(PDFAConformanceLevel newLevel) {
+        conformanceLevel = newLevel;
+        return this;
+    }
+
+    public ZUGFeRDExporterFromA1Factory ignoreA1Errors() {
+        this.ignoreA1Errors = true;
+        return this;
+    }
+
+    public ZUGFeRDExporterFromA1Factory setAttachZugferdHeaders(final boolean attachZugferdHeaders) {
+        this.attachZugferdHeaders = attachZugferdHeaders;
+        return this;
+    }
+
+    public ZUGFeRDExporterFromA1Factory setCreator(String creator) {
+        this.creator = creator;
+        return this;
+    }
+
+    public ZUGFeRDExporterFromA1Factory setProducer(String producer) {
+        this.producer = producer;
+        return this;
+    }
+}

mustang/src/main/java/org/mustangproject/ZUGFeRD/model/PDFAConformanceLevel.java

@@ -0,0 +1,15 @@
+package org.mustangproject.ZUGFeRD.model;
+
+public enum PDFAConformanceLevel {
+    ACCESSIBLE("A"), BASIC("B"), U("U");
+
+    private final String letter;
+
+    PDFAConformanceLevel(final String letter) {
+        this.letter = letter;
+    }
+
+    public String getLetter() {
+        return letter;
+    }
+}