XML Document validation with XML Schema

In todays blogpost, I will show you how to validate an XML-document to its XSD-schema. Before we begin, create an example XML-schema:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
 targetNamespace="http://javaeenotes.blogspot.com/schema"
 xmlns:tns="http://javaeenotes.blogspot.com/schema"
 elementFormDefault="qualified">
  <xs:element name="person">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="name" type="xs:string"/>
        <xs:element name="age" type="xs:integer"/>
        <xs:element name="birthdate" type="xs:date"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

You can use this schema to generate an XML-document with Eclipse:

<?xml version="1.0" encoding="UTF-8"?>
<tns:person
 xmlns:tns="http://javaeenotes.blogspot.com/schema"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation=
 "http://javaeenotes.blogspot.com/schema schema.xsd">
  <tns:name>Albert</tns:name>
  <tns:age>29s</tns:age>
  <tns:birthdate>1981-11-19</tns:birthdate>
</tns:person>

Now, the last thing we need to do, is to build the validator:

package com.javaeenotes;

import java.io.File;
import java.io.IOException;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.w3c.dom.Document;
import org.xml.sax.SAXException;

public class Main {
  private static final String SCHEMA = "schema.xsd";
  private static final String DOCUMENT = "document.xml";

  public static void main(String[] args) {
    Main m = new Main();
    m.validate();
  }

  public void validate() {
    DocumentBuilderFactory dbf =
      DocumentBuilderFactory.newInstance();
    dbf.setNamespaceAware(true);

    try {
      DocumentBuilder parser = dbf.newDocumentBuilder();
      Document document = parser.parse(new File(DOCUMENT));
      SchemaFactory factory = SchemaFactory
      .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

      Schema schema = null;
      schema = factory.newSchema(new File(SCHEMA));
      Validator validator = schema.newValidator();
      validator.validate(new DOMSource(document));
    } catch (SAXException e) {
      e.printStackTrace();
    } catch (IllegalArgumentException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } catch (ParserConfigurationException e) {
      e.printStackTrace();
    }
  }
}

The validator will throw an exception if the validation process fails. Based on the specific type of error, the following exceptions could be thrown:

• SAXException: XML-document not valid.


• IllegalArgumentException: XML-artifact/instruction not supported.


• IOException: document/schema file read error.


• ParserConfigurationException: parser could not be configured.