Question

I’ve run into a strange problem with JAXB. I’ve used xjc to generate my java classes from my XSD and all looks good. If I use schemagen, it produces a proper schema that matches my original xsd. However, if I use JAXBContext.generateSchema(), then the generated schema is incomplete.

I’m using Oracle Java 1.6.0_29 and jaxb-2.2.4-1.jar as the implementation. I’m enclosing the java code (which generates the schema), and the xsd below as well as the output of the jaxb call.

CalculateBorrowingDataResponse.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema 
    version="1.1"
    attributeFormDefault="unqualified" 
    elementFormDefault="qualified"
    targetNamespace="http://www.domain.com/ClientServices/LendingSimulation/CalculateBorrowingDataResponse" 
    xmlns:lssSt="http://www.domain.com/ClientServices/LendingSimulation/CalculateBorrowingDataResponse"
    xmlns:cbdRes="http://www.domain.com/ClientServices/LendingSimulation/CalculateBorrowingDataResponse" 
    xmlns:xsd="http://www.w3.org/2001/XMLSchema">


    <!-- CalculateBorrowingData -->
    <xsd:complexType name="CalculateBorrowingDataResponseType">
        <xsd:sequence>
            <xsd:element name="loanAgmt" type="cbdRes:LoanAgreementType" minOccurs="1" maxOccurs="1" />
        </xsd:sequence>
    </xsd:complexType>


    <xsd:complexType name="LoanAgreementType">
        <xsd:sequence>
            <xsd:element name="borrowingBasedPmtAmt" type="lssSt:borrowingBasedPmtAmt" minOccurs="0" maxOccurs="1" />
            <xsd:element name="maxPmtAmt" type="lssSt:maxPmtAmt" minOccurs="0" maxOccurs="1" />
            <xsd:element name="borrowingCapacityMin" type="lssSt:borrowingCapacityMin" minOccurs="0" maxOccurs="1" />
            <xsd:element name="borrowingCapacityMax" type="lssSt:borrowingCapacityMax" minOccurs="0" maxOccurs="1" />
            <xsd:element name="propertyValueMinAmt" type="lssSt:propertyValueMinAmt" minOccurs="0" maxOccurs="1" />
            <xsd:element name="propertyValueMaxAmt" type="lssSt:propertyValueMaxAmt" minOccurs="0" maxOccurs="1" />
        </xsd:sequence>
    </xsd:complexType>

    <xsd:element name="calculateBorrowingDataResponse" type="cbdRes:CalculateBorrowingDataResponseType"/>


    <xsd:simpleType name="borrowingBasedPmtAmt">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="maxPmtAmt">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="borrowingCapacityMin">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="borrowingCapacityMax">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="propertyValueMinAmt">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="propertyValueMaxAmt">
        <xsd:restriction base="xsd:decimal" >
        <xsd:totalDigits value="19" />
        <xsd:fractionDigits value="4" />
        </xsd:restriction>
    </xsd:simpleType>

</xsd:schema>

Java code:

    // Creating the XML tree
    JAXBContext jc = JAXBContext.newInstance( CalculateBorrowingDataResponseType.class );
    Unmarshaller u = jc.createUnmarshaller();

    // generate the schemas
    final List<ByteArrayOutputStream> schemaStreams = new ArrayList<ByteArrayOutputStream>();
    jc.generateSchema(new SchemaOutputResolver(){
        @Override
        public Result createOutput(String namespaceUri, String suggestedFileName) throws IOException {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            schemaStreams.add(out);
            StreamResult streamResult = new StreamResult(out);
            streamResult.setSystemId("");
            return streamResult;
        }});

    // convert to a list of string
    List<String> schemas = new ArrayList<String>();
    for( ByteArrayOutputStream os : schemaStreams )
    {
        schemas.add(os.toString());
        System.out.println( os.toString());
    }

Output of jaxbContext.generateSchema():

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema elementFormDefault="qualified" version="1.0" targetNamespace="http://www.domain.com/ClientServices/LendingSimulation/CalculateBorrowingDataResponse" xmlns:tns="http://www.domain.com/ClientServices/LendingSimulation/CalculateBorrowingDataResponse" xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:complexType name="CalculateBorrowingDataResponseType">
    <xs:sequence>
      <xs:element name="loanAgmt" type="tns:LoanAgreementType"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="LoanAgreementType">
    <xs:sequence>
      <xs:element name="borrowingBasedPmtAmt" type="xs:decimal" minOccurs="0"/>
      <xs:element name="maxPmtAmt" type="xs:decimal" minOccurs="0"/>
      <xs:element name="borrowingCapacityMin" type="xs:decimal" minOccurs="0"/>
      <xs:element name="borrowingCapacityMax" type="xs:decimal" minOccurs="0"/>
      <xs:element name="propertyValueMinAmt" type="xs:decimal" minOccurs="0"/>
      <xs:element name="propertyValueMaxAmt" type="xs:decimal" minOccurs="0"/>
    </xs:sequence>
  </xs:complexType>
</xs:schema>

As you can see, the output schema matches very closely, save and except that it is missing the element definition of calculateBorrowingDataResponse! If I use schemagen, however, the
calculateBorrowingDataResponse element is generated.

Am I missing something in my SchemaOutputResolver setup or doing something incorrect/incomplete? Or is this a bug in the Jaxb RI?

Answer 1

Change

JAXBContext.newInstance(CalculateBorrowingDataResponseType.class);

to

JAXBContext.newInstance(CalculateBorrowingDataResponseType.class.getPackage().getName());

JAXB needs the information defined in the package-info.java file (generated by xjc from your XSD) inside the above class’ package.

It doesn’t creates the XSD element in question, because CalculateBorrowingDataResponseType doesn’t have an @XmlRootElement annotation.

Why didn’t xjc create one from the beginning? See the most authoritative explanation on the Internets regarding this matter.

And why does your code generates the aforementioned element if you supply a package name to JAXBContext.newInstance(...) even though CalculateBorrowingDataResponseType still missing the @XmlRootAnnotation? I haven’t got the faintest idea! Now I have!