XML validation using javax.xml.validation

Question

Hello,
I am trying to validate some xml against my xsd.
Here is my xml:
<host>
    <status>Unknown</status>
</host>Here is my xsd:
<?xml version="1.0"?>
                                                                                                                                                             <xsd:schema targetNamespace="blah"
        xmlns:tns="blah"
        xmlns:xsd="blah">
<xsd:simpleType name="Status">
<xsd:restriction base="xsd:string">
  <xsd:enumeration value="Unknown"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:element name="host">
   <xsd:complexType>
     <xsd:all>
       <xsd:element name="status" type="tns:Status"/>
     </xsd:all>
   </xsd:complexType>
</xsd:element>
                                                                                                                                                             </xsd:schema>My test code is:
        try
            DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document document = parser.parse(new File("test.xml"));
            // Create a SchemaFactory capable of understanding WXS schemas.
            SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            // Load a WXS schema, represented by a Schema instance.
            StreamSource schemaFile = new StreamSource(new File("schema.xsd"));
            Schema schema = factory.newSchema(schemaFile);
            // Create a Validator object, which can be used to validate the document
            Validator validator = schema.newValidator();
            // Validate the DOM tree.
            validator.validate(new DOMSource(document));
        catch(Exception e)
            fail("XML validation failed: " + e.getMessage());
        }I get the following error:
ERROR: 'cvc-elt.1: Cannot find the declaration of element 'host'.'
If i replace "type=tns:Status' in the "status" element with just "type=string", it works fine.
Does anyone have any idea what the problem is?
Thank you,
David

Answer 1

To daft_davy:
1. Your XSD document is invalid: the xmlns attribute of schema documents must always have the following value: "http://www.w3.org/2001/XMLSchema"
All other values will result in the following validation error:
org.xml.sax.SAXParseException: s4s-elt-schema-ns: The namespace of element 'schema' must be from the schema namespace, 'http://www.w3.org/2001/XMLSchema'.
Your XSD should look like this:
<?xml version="1.0"?>
<xsd:schema targetNamespace="blah" xmlns:tns="blah" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:simpleType name="Status">
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="Unknown"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:element name="host">
    <xsd:complexType>
      <xsd:all>
        <xsd:element name="status" type="tns:Status"/>
      </xsd:all>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>2. Your XML document does not match the XSD schema (even if you use the one above) for the following reasons:
a) The root element of the XML document must be associated with the namespace defined by the targetNamespace attribute of the schema.
b) The "blah" namespace at the element <status> in the XML document has to be undeclared because there is no namespace declaration to this element in the schema document either. There are to ways to do this:
<host xmlns="blah">
  <status xmlns="">Unknown</status>
</host>or:
<xxx:host xmlns:xxx="blah">
  <status>Unknown</status>
</xxx:host>
To watertownjordan:
The namespace URI can be virtually any string, so you don't need to specify a valid URI to define a namespace.