ABAP Validator

Abapvalidator.java

import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamSource;00
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;
import java.io.*;

/**
 * Created by abramsbn on 28-1-2016.
 * This class only validates an input XML against an XSD.
 */
public class AbapXmlValidator{

    public static void main(String [] args) throws FileNotFoundException {
        if (args.length != 2) {
            error_no_input();
            return;
        }
        DocumentBuilder xml_builder;
        Document xml_document;
        InputStream xml_source = new FileInputStream(new File(args[1]));
        InputStream xsd_stream = new FileInputStream(new File(args[0]));
        SchemaFactory schema_builder = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        Source schema_source = new StreamSource(xsd_stream);
        Schema schema;
        Validator schema_validator;
        try {
            xml_builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        }
        catch(ParserConfigurationException parser_error) {
            java_error(parser_error);
            return;
        }
        try {
            xml_document = xml_builder.parse(xml_source);
        }
        catch (SAXException e) {
            error_no_xml(e);
            return;
        }
        catch (IOException e) {
            java_error(e);
            return;
        }
        try {
            schema = schema_builder.newSchema(schema_source);
        } catch (SAXException e) {
            error_xsd_invalid(e);
            return;
        }
        schema_validator = schema.newValidator();
        try {
            schema_validator.validate(new DOMSource(xml_document));
        } catch (SAXException e) {
            error_xml_invalid(e);
            return;
        } catch (IOException e) {
            java_error(e);
            return;
        }
    }
    private static void java_error(Exception e) {
        System.out.println(e.getMessage());
    }
    private static void error_xml_invalid(Exception e) {
        java_error(e);
    }
    private static void error_xsd_invalid(Exception e) {
        java_error(e);
    }
    private static void error_no_xml(Exception e) {
        java_error(e);
    }
    private static void error_no_input() {
        help();
    }
    private static void help() {
        System.out.println("Usage: java -jar spv.jar \"<path_to_xsd>\" \"<path_to_xml>\"");
    }
}