XSD Tutorials - Herong's Tutorial Examples - v5.23, by Herong Yang
XSD Schema XML DOM Validator - XsdSchemaDomValidator.java
This section describes a tutorial example on how to create a Validator instance from an XSD Schema instance to validate an XML file using the JAXP DOM interface.
After creating an XSD Schema instance from the XSD schema file, we are ready to create a Validator instance from the schema instance. This Validator instance can then be used to validate an XML file represented with the DOM interface or the SAX interface.
Let's try the DOM interface first. If you need to learn DOM interface, you can read the XML file DOM parser tutorial example described in another chapter of this book.
Here is a tutorial example program called XsdSchemaDomValidator.java that validates an XML file against an XSD file using the DOM interface:
/* XsdSchemaDomValidator.java - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved. */ import javax.xml.validation.SchemaFactory; import javax.xml.validation.Schema; import javax.xml.XMLConstants; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.DocumentBuilder; import org.w3c.dom.Document; import javax.xml.validation.Validator; import javax.xml.transform.dom.DOMSource; import java.io.File; class XsdSchemaDomValidator { public static void main(String[] a) { if (a.length<2) { System.out.println("Usage:"); System.out.println("java XsdSchemaValidator schema_file_name " + "xml_file_name"); } else { String schemaName = a[0]; String xmlName = a[1]; Schema schema = loadSchema(schemaName); Document document = parseXmlDom(xmlName); validateXml(schema, document); } } public static void validateXml(Schema schema, Document document) { try { // creating a Validator instance Validator validator = schema.newValidator(); System.out.println(); System.out.println("Validator Class: " + validator.getClass().getName()); // validating the document against the schema validator.validate(new DOMSource(document)); System.out.println(); System.out.println("Validation passed."); } catch (Exception e) { // catching all validation exceptions System.out.println(); System.out.println(e.toString()); } } public static Schema loadSchema(String name) { Schema schema = null; try { String language = XMLConstants.W3C_XML_SCHEMA_NS_URI; SchemaFactory factory = SchemaFactory.newInstance(language); schema = factory.newSchema(new File(name)); } catch (Exception e) { System.out.println(e.toString()); } return schema; } public static Document parseXmlDom(String name) { Document document = null; try { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); document = builder.parse(new File(name)); } catch (Exception e) { System.out.println(e.toString()); } return document; } }
As the first test, let's try to validate the following simple XML file, first_html.xml, against the simple XSD schema file, first_html.xsd:
herong> type first_html.xsd <?xml version = "1.0" encoding = "utf-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xs:element name="html" type="htmlType"/> <xs:complexType name="htmlType"> <xs:sequence> <xs:element name="body" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:schema> herong> type first_html.xml <?xml version = "1.0" encoding = "utf-8"?> <html> <body>My first HTML document in XML format.</body> </html> herong> javac XsdSchemaDomValidator.java herong> java XsdSchemaDomValidator first_html.xsd first_html.xml Validator Class: com.sun.org.apache.xerces.internal.jaxp .validation.ValidatorImpl Validation passed.
The output shows that:
Table of Contents
XML Editor and Schema Processor - XMLPad
Java API for XML Processing - JAXP
►JAXP - XML Schema (XSD) Validation
Standard Steps to Validate XML Documents Against a Schema
XSD Schema File Loader - XsdSchemaLoader.java
XSD Schema File Loading Errors
►XSD Schema XML DOM Validator - XsdSchemaDomValidator.java
XSD Schema XML DOM Validation Errors
XSD Schema XML DOM Validator with Error Handler
XSD Schema XML SAX Validator - XsdSchemaSaxValidator.java
XSD Schema XML SAX Validation Errors
XSD Schema XML SAX Validator with Error Handler
XSD Schema XML Validator - Final Version
XSD 1.1 Not Supported in JDK 13
Xerces2 Java Parser - Java API of XML Parsers
Introduction of XSD Built-in Datatypes
"string" and Its Derived Datatypes
"decimal" and Its Derived Datatypes
"dateTime" and Its Related Datatypes
Miscellaneous Built-in Datatypes
Facets, Constraining Facets and Restriction Datatypes
"simpleType" - Defining Your Own Simple Datatypes
Identity-Constraints: unique, key and keyref
Assertion as Custom Validation Rules
XML Schema Location and Namespace in XML Documents
Overriding Element Types in XML Documents