How to read Xsd-Annotations from Xsd-Schema using Apache XMLBeans?

How to read Xsd-Annotations from Xsd-Schema using Apache XMLBeans?

I read a xsd-schema file using Apache XMLBeans, iterating over all SchemaProperties beginning with the root element.
At each SchemaProperty I am looking for an annotation with: schemaProperty.getType().getAnnotation(), but I don't find any annotation. (java code below)

I examine for example the following xsd-file:

Figure of xsd structure:

figure of xsd structure

Xsd source code:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xs:element name="ExterneDaten" type="ExterneDaten"> <xs:annotation> <xs:documentation>annotation for ExterneDaten</xs:documentation> </xs:annotation> </xs:element> <xs:complexType name="ExterneDaten"> <xs:annotation> <xs:documentation>annotation for Type ExterneDaten</xs:documentation> </xs:annotation> <xs:sequence> <xs:element name="value1" type="xs:string"> <xs:annotation> <xs:documentation>annotation for value1</xs:documentation> </xs:annotation> </xs:element> </xs:sequence> <xs:attribute name="isTest" type="xs:boolean"> <xs:annotation> <xs:documentation>annotation for boolean attribute isTest</xs:documentation> </xs:annotation> </xs:attribute> </xs:complexType>

I examine the xsd with my function: MyXsdReader.readAllAnnotationsFromXsd(String schema);

Here is the java code:

public class MyXsdReader { public static void readAllAnnotationsFromXsd(String newSchema) { try { SchemaTypeLoader loader = XmlBeans.typeLoaderForClassLoader(SchemaDocument.class.getClassLoader()); XmlObject xmlObjects = new XmlObject[1]; XmlOptions options = new XmlOptions(); options.setLoadLineNumbers().setLoadMessageDigest().setCharacterEncoding("utf-8"); options.setCompileDownloadUrls(); xmlObjects[0] = loader.parse(newSchema, null, options); SchemaTypeSystem sts = XmlBeans.compileXsd(xmlObjects, XmlBeans.getBuiltinTypeSystem(), options); readXsdRootElement(sts); } catch (Exception e) { System.out.println("makeXsdListRootEle(): Excpetion: " + e.getMessage()); } } private static void readXsdRootElement(SchemaTypeSystem sts) { SchemaGlobalElement globals = sts.globalElements(); if (globals != null && globals.length == 1) { SchemaGlobalElement sge = globals[0]; SchemaType st = sge.getType(); SchemaProperty properties = st.getProperties(); for (int k = 0; k < properties.length; k++) { SchemaProperty property = properties[k]; checkAnnotation(property); if (property.isAttribute() == false) { readXsdProperty(property); } } } } private static void readXsdProperty(SchemaProperty property) { SchemaProperty properties = property.getType().getProperties(); for (SchemaProperty schemaProperty : properties) { checkAnnotation(schemaProperty); readXsdProperty(schemaProperty); } } private static void checkAnnotation(SchemaProperty schemaProperty) { SchemaAnnotation annotation = schemaProperty.getType().getAnnotation(); if (annotation != null) { System.out.println(annotation.toString()); } } }

What do I have to do, to be able to read the annotations inside the xsd?

A solution was already shown here: stackoverflow.com/questions/42965146/…
– Gio
Jan 28 at 12:40

But this solution above does not read annotations declared directly as children of elements but only annotations that are declared as children of type definitions. So in the example above "<xs:documentation>annotation for ExterneDaten</xs:documentation>" will not be read but the following will be read: <xs:documentation>annotation for Type ExterneDaten</xs:documentation>
– Gio
Jan 28 at 12:54

1 Answer
1

I had the same requirement and was able to parse the Annotations in XSD as shown below.

Say the XSD is as follows:-

Now, we have to create a custom Annotation Parser as follows :-

public class XSDAnnotaionParser extends AnnotationParser { private StringBuilder documentation = new StringBuilder(); @Override public ContentHandler getContentHandler(AnnotationContext context, String parentElementName, ErrorHandler handler, EntityResolver resolver) { return new ContentHandler() { private boolean parsingDocumentation = false; @Override public void characters(char ch, int start, int length) throws SAXException { if (parsingDocumentation) { documentation.append(ch, start, length); } } @Override public void endElement(String uri, String localName, String name) throws SAXException { //say you want to parse the text in "documentaion" tag in your xsd....this is where we scpecify the tag if (localName.equals("documentation")) { parsingDocumentation = false; } } @Override public void startElement(String uri, String localName, String name, Attributes atts) throws SAXException { if (localName.equals("documentation")) { parsingDocumentation = true; } } @Override public void setDocumentLocator(Locator locator) { // TODO Auto-generated method stub } @Override public void startDocument() throws SAXException { // TODO Auto-generated method stub } @Override public void endDocument() throws SAXException { // TODO Auto-generated method stub } @Override public void startPrefixMapping(String prefix, String uri) throws SAXException { // TODO Auto-generated method stub } @Override public void endPrefixMapping(String prefix) throws SAXException { // TODO Auto-generated method stub } @Override public void ignorableWhitespace(char ch, int start, int length) throws SAXException { // TODO Auto-generated method stub } @Override public void processingInstruction(String target, String data) throws SAXException { // TODO Auto-generated method stub } @Override public void skippedEntity(String name) throws SAXException { // TODO Auto-generated method stub } }; } @Override public Object getResult(Object existing) { return documentation.toString().trim(); } }

Now we create a factory class for the custom annotation parser which we clreated above as follows :-

class AnnotationFactory implements AnnotationParserFactory { @Override public AnnotationParser create() { return new XSDAnnotaionParser(); } }

Now we add the custom annotaion parser to XSOMParser which we use for parsing XSD as follows:-

XSOMParser parser = new XSOMParser(); parser.setAnnotationParser(new AnnotationFactory()); try { parser.parse(xml); } catch (SAXException ex) { throw new SchemaException(ex); }

For parsing the documentation tag we can use code as below:-

XSSchemaSet schemaSet = null; try { schemaSet = parser.getResult(); } catch (SAXException ex) { throw new SchemaException(ex); } Iterator<XSElementDecl> iterator = schemaSet.iterateElementDecls(); while (iterator.hasNext()) { XSElementDecl elementDecl= (XSElementDecl) iterator.next(); XSComplexType eleCompDecl= elementDecl.getType().asComplexType(); if (eleCompDecl!= null) { //we get the annotation here XSAnnotation annotaion = eleCompDecl.getAnnotation(); //this will print the tezxt inside documentaion tag System.out.println(annotaion.getAnnotation()); } }

Code for reading annotaions inside attributes of an xsd is as follows :-

Collection<? extends XSAttributeUse> attributes= eleCompDecl.getAttributeUses(); Iterator<? extends XSAttributeUse> iterator = attributes.iterator(); while(attributes.hasNext()) { XSAttributeUse next = attributes.next(); XSAttributeDecl attributeDecl = next.getDecl(); //vivek String desc = null; if(attributeDecl != null) { try { desc = (String)attributeDecl.getAnnotation().getAnnotation(); System.out.println("the documentaion for the attribute is "+desc) } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } }

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