javaxmlxsdxmlreadersaxparser

SAXParser does not invoke warning on "schema_reference.4: Failed to read schema document"

I'm trying to validate an XML using SAXParser. The XML is deliberately pointing to a non-existent schema document but SAX does not invoke a warning, as I would expect it to.

When validating the XML using Eclipse's validate mechanisms, it correctly flags the file with a warning:

schema_reference.4: Failed to read schema document 'schema', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.

When executing the test method, neither System.out is printed to, nor a SAXException (or any Exception, for that matter) is thrown.

The test method

@Test
public void testSaxParser_missingSchema() throws ParserConfigurationException, SAXException, IOException {
  // Arrange
  final String resourcesFolder = "src/test/resources/XML_missing_schema.xml";

  // Act
  SAXParserFactory spf = SAXParserFactory.newInstance();
  spf.setNamespaceAware(true);
  SAXParser saxParser = spf.newSAXParser();
  XMLReader xmlReader = saxParser.getXMLReader();
  xmlReader.setErrorHandler(new LocalErrorHandler());
  xmlReader.parse(toBeValidated);  // does not throw anything, test passes
}

Class LocalErrorHandler

class LocalErrorHandler implements ErrorHandler {

  @Override
  public void warning(SAXParseException exception) throws SAXException {
    System.out.println(exception);
    throw exception;
  }

  @Override
  public void error(SAXParseException exception) throws SAXException {
    System.out.println(exception);
    throw exception;
  }

  @Override
  public void fatalError(SAXParseException exception) throws SAXException {
    System.out.println(exception);
    throw exception;
  }
}

src/test/resources/XML_missing_schema.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xml>
<Type xsi:schemaLocation="namespace schema"
  xmlns="namespace" xmlns:schemaNs="namespace/schemaNs"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
</Type>

What I've tried

Environment

C:\eclipse\jdk8\bin>java.exe -version
openjdk version "1.8.0_265"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_265-b01)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.265-b01, mixed mode)

C:\eclipse>type .eclipseproduct
name=Eclipse Platform
id=org.eclipse.platform
version=4.15.0

<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13</version>
    <scope>test</scope>
  </dependency>
</dependencies>
Solution

  • Enable XML Schema validation by setting its feature to true:

    xmlReader.setFeature("http://apache.org/xml/features/validation/schema", true);

    The default is false, so without that call, no XSD validation is performed.

    See also