XSD Parser Kotlin

DOMParserDemo.kt

import org.w3c.dom.Document
import org.xml.sax.SAXException
import org.xml.sax.SAXParseException
import org.xml.sax.helpers.DefaultHandler
import java.io.StringReader
import javax.xml.XMLConstants
import javax.xml.parsers.DocumentBuilderFactory
import javax.xml.transform.stream.StreamSource
import javax.xml.validation.SchemaFactory

//private fun setFeature(parser: DOMParser, feature: String, setting: Boolean) {
//    parser.setFeature(feature, setting)
//}

fun Document.getTextByName(name: String) = this.getElementsByTagName(name)?.item(0)?.textContent

fun main(args: Array<String>) {
    val sources: Array<StreamSource> = arrayOf(StreamSource(StringReader(xsd)))
    val factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI)
    val schema = factory.newSchema(sources)

    val dbf = DocumentBuilderFactory.newInstance()
    dbf.isNamespaceAware = true
    dbf.schema = schema
    val db = dbf.newDocumentBuilder()
    db.setErrorHandler(SAXParserErrorHandler1())
    try {
        val doc = db.parse(xml.byteInputStream())
        println(doc.getTextByName("checksum"))
    } catch (e: SAXException) {
        println(e)
    }
}

class SAXParserErrorHandler1 : DefaultHandler() {
    override fun warning(ex: SAXParseException) {
        error(ex)
    }

    override fun error(ex: SAXParseException) {
        throw ex
    }

    override fun fatalError(ex: SAXParseException) {
        error(ex)
    }
}

val xml = """<?xml version="1.0"?>
<quotations
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>
    <quote quoteid="A42">
        <saying>
            I love deadlines. I like the whooshing sound
            they make as they fly by.
        </saying>
        <attribution>Douglas Adams</attribution>
        <era>Modern</era>
        <checksum>1111111</checksum>

    </quote>
    <quote quoteid="H3">
        <saying>
            My goal is simple. It is complete understanding
            of the universe, why it is as it is and why
            it exists at all.
        </saying>
        <attribution>Stephen Hawking</attribution>
        <era>Modern</era>
    </quote>
    <quote quoteid="U1">
        <saying>
            Some people make things happen, somße watch while
            things happen, and some wonder "What happened?"
        </saying>
        <attribution>Unknown</attribution>
        <era>Modern!@</era>
    </quote>
</quotations>"""
val xsd = """<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="quotations">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="quote" minOccurs="0" maxOccurs="unbounded">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="saying" type="xs:string"/>
                            <xs:element name="attribution" type="xs:string"/>
                            <xs:element name="era" type="String"/>
                            <xs:element name="checksum" type="xs:string" minOccurs="0"/>
                        </xs:sequence>
                        <xs:attribute name="quoteid" type="xs:string"/>
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
    <xs:simpleType name="String">
        <xs:restriction base="xs:string">
            <xs:pattern value="[\w@]+"/>
        </xs:restriction>
    </xs:simpleType>
</xs:schema>"""

//""" <dependency>
//            <groupId>xerces</groupId>
//            <artifactId>xercesImpl</artifactId>
//            <version>2.12.2</version>
//        </dependency>"""