Validating XML against multiple schemas extracted from WSDL

Question

I'm trying to manually handle a Web Service request using SAAJ, but still validate the received request against the schema of the WSDL for the web service. This particular WSDL contains multiple elements, which I extract using wsdl4j, and when I get to the point where I try to create a new Validator, I'm getting an error message about the Validator not being able to resolve a reference inside one schema to an element defined in another:

org.xml.sax.SAXParseException; src-resolve: Cannot resolve the name 'ns0:CustomerNumber' to a(n) 'element declaration' component.

I've wittled the actual WSDL and code down to something small to create something reproducable. The "simple.wsdl" loads correctly in Soap-UI as well. This is on Windows 7 with jdk1.7.0_51.

Note that the original WSDL with which I noticed this issue was generated by TIBCO BusinessWorks, so I don't believe this is an issue of invalid WSDL.

I have seen other questions on SO that are similar to this, but the solutions provided don't seem to fully meet my scenario, so I figured I'd ask again.

Does anybody have any idea what's going on and how I can get this working?

Test Code:

import java.util.ArrayList;

import javax.wsdl.Definition;
import javax.wsdl.extensions.schema.Schema;
import javax.wsdl.factory.WSDLFactory;
import javax.wsdl.xml.WSDLReader;
import javax.xml.XMLConstants;
import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.junit.Test;
import org.w3c.dom.Element;

public class TestIt {
    @Test
    public void testWSDLSchema() throws Exception {
        WSDLFactory wsdlFactory    = WSDLFactory.newInstance();
        WSDLReader reader         = wsdlFactory.newWSDLReader();
        Definition wsdlDefinition = reader.readWSDL("test/resources/simple.wsdl");

        ArrayList<Element> wsdlSchemas = new ArrayList<Element>();

        for (Object o : wsdlDefinition.getTypes().getExtensibilityElements()) {
            if (o instanceof Schema) {
                wsdlSchemas.add(((Schema) o).getElement());
            }
        }

        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        ArrayList<DOMSource> asrcs   = new ArrayList<DOMSource>();

        for (Element e : wsdlSchemas) {
            asrcs.add(new DOMSource(e));
        }
        DOMSource sources[] = asrcs.toArray(new DOMSource[0]);
        javax.xml.validation.Schema schema  = factory.newSchema(sources);

        Validator schemaValidator = schema.newValidator();
    }
}

Full stack trace:

Retrieving document at 'test/resources/simple.wsdl'.

org.xml.sax.SAXParseException; src-resolve: Cannot resolve the name 'ns0:CustomerNumber' to a(n) 'element declaration' component.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:198)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:134)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:437)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:347)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaErr(XSDHandler.java:4166)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaError(XSDHandler.java:4145)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.getGlobalDecl(XSDHandler.java:1678)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDElementTraverser.traverseLocal(XSDElementTraverser.java:170)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.traverseLocalElements(XSDHandler.java:3618)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.parseSchema(XSDHandler.java:633)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema(XMLSchemaLoader.java:616)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar(XMLSchemaLoader.java:574)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar(XMLSchemaLoader.java:540)
    at com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory.newSchema(XMLSchemaFactory.java:252)
    at TestIt.testWSDLSchema(TestIt.java:37)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:202)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

WSDL:

<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions xmlns:ns10="http://www.abc.com/ServiceA"
                  xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
                  xmlns:ns13="http://www.abc.com/Common"
                  xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
                  xmlns:ns2="http://www.abc.com/DetailsResponse"
                  xmlns:ns3="http://www.abc.com/ErrorSchema"
                  xmlns:ns1="http://www.abc.com/DetailsRequest"
                  xmlns:tns="http://www.abc.com/Service"
                  name="Untitled"
                  targetNamespace="http://www.abc.com/Service">
    <wsdl:types>
        <xs:schema
                xmlns="http://www.abc.com/DetailsRequest"
                xmlns:ns0="http://www.abc.com/Common"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                targetNamespace="http://www.abc.com/DetailsRequest"
                elementFormDefault="qualified"
                attributeFormDefault="unqualified">
            <xs:import namespace="http://www.w3.org/XML/1998/namespace"/>
            <xs:import namespace="http://www.abc.com/Common"/>
            <xs:element name="DetailsRequest">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element ref="ns1:RequestBody"/>
                    </xs:sequence>
                </xs:complexType>
            </xs:element>
            <xs:element name="RequestBody">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element ref="ns0:CustomerNumber"/>
                    </xs:sequence>
                </xs:complexType>
            </xs:element>
        </xs:schema>
        <xs:schema
                xmlns="http://www.abc.com/DetailsResponse"
                xmlns:ns0="http://www.abc.com/Common"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                targetNamespace="http://www.abc.com/DetailsResponse"
                elementFormDefault="qualified"
                attributeFormDefault="unqualified">
            <xs:import namespace="http://www.abc.com/Common"/>
            <xs:element name="DetailsResponse">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element ref="ns0:AccountNumber"/>
                    </xs:sequence>
                </xs:complexType>
            </xs:element>
        </xs:schema>
        <xs:schema
                xmlns="http://www.abc.com/Common"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                targetNamespace="http://www.abc.com/Common"
                elementFormDefault="qualified"
                attributeFormDefault="unqualified">
            <xs:element name="CustomerNumber">
                <xs:simpleType>
                    <xs:restriction base="xs:string">
                        <xs:maxLength value="20"/>
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
            <xs:element name="AccountNumber">
                <xs:simpleType>
                    <xs:restriction base="xs:string">
                        <xs:maxLength value="20"/>
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:schema>
        <xs:schema
                xmlns="http://www.abc.com/ErrorSchema"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                targetNamespace="http://www.abc.com/ErrorSchema"
                elementFormDefault="qualified"
                attributeFormDefault="unqualified">
            <xs:element name="ErrorSchema">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element name="ErrorResponseBody" type="xs:string"/>
                    </xs:sequence>
                </xs:complexType>
            </xs:element>
        </xs:schema>
    </wsdl:types>
    <wsdl:service name="ServiceA">
        <wsdl:port name="ServiceAEndpoint" binding="tns:ServiceABinding">
            <soap:address location="http://localhost:7232/ServiceA/ServiceAEndpoint"/>
        </wsdl:port>
    </wsdl:service>
    <wsdl:portType name="ServiceA">
        <wsdl:operation name="GetDetails">
            <wsdl:input message="tns:DetailsRequest"/>
            <wsdl:output message="tns:DetailsResponse"/>
            <wsdl:fault name="fault1" message="tns:DetailsErrorResponse"/>
        </wsdl:operation>
    </wsdl:portType>
    <wsdl:binding name="ServiceABinding" type="tns:ServiceA">
        <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
        <wsdl:operation name="GetDetails">
            <soap:operation style="document" soapAction="/ServiceA/ServiceAEndpoint/GetDetails"/>
            <wsdl:input>
                <soap:body use="literal" parts="DetailsRequest"/>
            </wsdl:input>
            <wsdl:output>
                <soap:body use="literal" parts="DetailsResponse"/>
            </wsdl:output>
            <wsdl:fault name="fault1">
                <soap:fault use="literal" name="fault1"/>
            </wsdl:fault>
        </wsdl:operation>
    </wsdl:binding>
    <wsdl:message name="DetailsRequest">
        <wsdl:part name="DetailsRequest" element="ns1:DetailsRequest"/>
    </wsdl:message>
    <wsdl:message name="DetailsResponse">
        <wsdl:part name="DetailsResponse" element="ns2:DetailsResponse"/>
    </wsdl:message>
    <wsdl:message name="DetailsErrorResponse">
        <wsdl:part name="DetailsErrorResponse" element="ns3:ErrorSchema"/>
    </wsdl:message>
</wsdl:definitions>

did you try supplying the schemas in the opposite order of the imports? — jtahlborn, Jan 20 '14 at 16:10
I did, and in this simple case it works. I just use wsdlSchemas.add(0, ...) to reverse the order in the code without modifying the actual WSDL. However, with the real WSDL, this doesn't help. I guess the dependencies are a bit tricker to figure out in that case? — Maarten Boekhold, Jan 20 '14 at 16:31
Since in the simple test case I can get it to work by just changing the order of the Source[] entries, I'm not sure an LSResourceResolver should be needed here? — Maarten Boekhold, Jan 20 '14 at 17:55
you seemed to imply that re-ordering didn't help in the complex case. how do you plan to solve that without the LSResourceResolver? — jtahlborn, Jan 20 '14 at 18:36
Hi, I suppose I'm a bit confused about the purpose of LSResourceResolver. My understanding is that you use it to **pull** in external 'schema parts/namespaces' that are not available in the information already provided to factory.newSchema(Source[]). And in my case, I already **have** provided all 'parts' of the schema, it's just that Xerces(?) doesn't seem to realize that. OK, so I'll try an LSResourceResolver. Question: I don't have my schema parts available as plain text. I only have it in DOM model. How to I fit that into an LSInput implementation? — Maarten Boekhold, Jan 21 '14 at 05:33
As i mentioned in my answer, the SchemaFactory is dumb. it doesn't do any lookahead, so it requires all the schemas to be in the right order by default (if possible). by using a custom `LSResourceResolver`, you can provide the other schemas on demand. we have similar functionality in our code-base. i believe we just write the schemas to a temp file in order to provide it as an `LSInput`. — jtahlborn, Jan 21 '14 at 14:50
Re "doesn't do lookahead"... I wonder if that means that the JAXP implementation is non-compliant to the specifications, which say "The resulting schema contains components from the specified sources. The same result would be achieved if all these sources were imported, using appropriate values for schemaLocation and namespace, into a single schema document with a different targetNamespace and no components of its own, if the import elements were given in the same order as the sources". Needs more thinking. — Maarten Boekhold, Jan 22 '14 at 08:10

score 1 · Answer 1 · answered Jul 03 '18 at 12:45

I had to both use a LSResourceResolver and copy namespace declarations from the wsdl document to the schema elements to make this work. Here is the code:

public static Schema makeSchema(String pathToWsdl)
    throws ParserConfigurationException, IOException, SAXException, InstantiationException, IllegalAccessException, ClassNotFoundException {
    // read wsdl document
    File wsdlFile = new File(pathToWsdl);
    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    dbFactory.setNamespaceAware(true);
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    Document wsdlDoc = dBuilder.parse(wsdlFile);

    // read namespace declarations from wsdl document, in case they are referred from a schema
    NamedNodeMap attributes = wsdlDoc.getDocumentElement().getAttributes();
    Map<String, String> namespacesFromWsdlDocument = new HashMap<>();
    for (int i = 0; i < attributes.getLength(); i++) {
        Node n = attributes.item(i);
        if (n.getNamespaceURI() != null && n.getNamespaceURI().equals("http://www.w3.org/2000/xmlns/")) {
            namespacesFromWsdlDocument
                .put(n.getLocalName(), n.getNodeValue());
        }
    }

    // read the schema nodes from the wsdl
    NodeList schemas = wsdlDoc.getElementsByTagNameNS("http://www.w3.org/2001/XMLSchema", "schema");
    Map<String, DOMSource> sources = new HashMap<>();
    for (int i = 0; i < schemas.getLength(); i++) {
        // create a document for each schema and copy the source schema
        Document schema = dBuilder.newDocument();
        Element schemaElement = (Element)schema.importNode(schemas.item(i), true);

        // add all non-existing namespace declarations from the wsdl node
        String targetNs = schemaElement.getAttribute("targetNamespace");
        for (Map.Entry<String, String> ns : namespacesFromWsdlDocument.entrySet()) {
            String name = ns.getKey();
            String value = ns.getValue();
            if (schemaElement.getAttributeNodeNS("http://www.w3.org/2000/xmlns/", name) == null) {
                schemaElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:" + name, value);
            }
        }

        // map schemas by their target namespace
        schema.appendChild(schemaElement);
        DOMSource domSource = new DOMSource(schema);
        sources.put(targetNs, domSource);
    }

    SchemaFactory factory =
        SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

    // Create a ResourceResolver that can find the correct schema from the map
    DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();

    final DOMImplementationLS domImplementationLS = (DOMImplementationLS) registry.getDOMImplementation("LS");
    factory.setResourceResolver(new LSResourceResolver() {
        @Override public LSInput resolveResource(String type, String namespaceURI, String publicId, String systemId, String baseURI) {
            Source xmlSource = sources.get(namespaceURI);
            if (xmlSource != null) {
                LSInput input = domImplementationLS.createLSInput();
                ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
                Result outputTarget = new StreamResult(outputStream);
                try {
                    TransformerFactory.newInstance().newTransformer().transform(xmlSource, outputTarget);
                } catch (TransformerException e) {
                    e.printStackTrace();
                }
                InputStream is = new ByteArrayInputStream(outputStream.toByteArray());
                input.setByteStream(is);
                input.setSystemId(systemId);
                return input;
            } else {
                return null;
            }
        }
    });

    // create the schema object from the sources
    return factory.newSchema(sources.values().toArray(new DOMSource[]{}));
}

Also answered the same here: Java, Validate XML against an embedded schema in WSDL

score 0 · Answer 2 · answered Jan 20 '14 at 16:13

0

I think the SchemaFactory is being "dumb" about how it results imports. I believe if you provide the schemas in the opposite order (lowest level to highest level), that should work. In a situation where you have more complicated dependencies (or multiple schemas for the same namespace), you probably need to implement a custom LSResourceResolver and set it on the SchemaFactory.

answered Jan 20 '14 at 16:13

jtahlborn

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Are you sure? The javadocs for SchemaFactory.newSchema(Source[]) says: "The resulting schema contains components from the specified sources. The same result would be achieved if all these sources were imported, using appropriate values for schemaLocation and namespace, into a single schema document with a different targetNamespace and no components of its own, if the import elements were given in the same order as the sources". I could be reading this wrong, but to me this sounds like an LSResourceResolver should not be necessary. – Maarten Boekhold Jan 20 '14 at 17:54
@MaartenBoekhold - i'm not sure how your synthetic schema helps anything. you have to provide the imported schemas before the imports, so the synthetic schema would end up being last anyways? – jtahlborn Jan 20 '14 at 18:35

Validating XML against multiple schemas extracted from WSDL

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