com.crabshue.commons.xml.validation.XmlValidator Maven / Gradle / Ivy

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package com.crabshue.commons.xml.validation;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import javax.xml.XMLConstants;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.SAXException;

import com.crabshue.commons.exceptions.ApplicationException;
import com.crabshue.commons.exceptions.SystemException;
import com.crabshue.commons.exceptions.ValidationException;
import com.crabshue.commons.file.exceptions.FileErrorContext;
import com.crabshue.commons.file.exceptions.FileErrorType;
import com.crabshue.commons.xml.exceptions.XmlErrorContext;
import com.crabshue.commons.xml.exceptions.XmlErrorType;
import com.crabshue.commons.xml.schema.XmlSchemaUtils;

/**
 * Utility class for XML validation.
 *
 */
public class XmlValidator {

    private static Logger logger = LoggerFactory.getLogger(XmlValidator.class);

    /**
     * Validate an {@link File XML file} against a given schema.
     *
     * @param xmlFile   the XML file.
     * @param schemaUrl the URL of the remote schema.
     */
    public static void validateXmlAgainstSchema(final File xmlFile, final URL schemaUrl) {
        Validate.notNull(xmlFile);
        Validate.notNull(schemaUrl);

        try (InputStream xmlIs = FileUtils.openInputStream(xmlFile)) {
            final SchemaFactory schemaFactory = SchemaFactory
                .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            final Schema schema = schemaFactory.newSchema(schemaUrl);
            final Validator validator = schema.newValidator();
            validator.validate(new StreamSource(xmlIs));
        } catch (SAXException e) {
            throw new ValidationException(XmlErrorType.XML_INVALID_AGAINST_SCHEMA, "xml invalid against its schema", e)
                .addContextValue(XmlErrorContext.XML_FILE, xmlFile);
        } catch (IOException e) {
            throw new SystemException(FileErrorType.ERROR_READING_FILE, e)
                .addContextValue(FileErrorContext.FILE, xmlFile);
        }

    }

    /**
     * Validate an {@link File XML file} against the schema declared in the XML file.
     *
     * The schema must be found in the current folder {@code new File(".")}
     *
     * @param xmlFile the XML file.
     * @see #validateXml(File, File)
     */
    public static void validateXml(final File xmlFile) {
        validateXml(xmlFile, new File("."));
    }

    /**
     * Validate an {@link File XML file} against the schema declared in the XML file.
     *
     * The schema must be found in the given schem folder
     *
     * @param xmlFile      the XML file.
     * @param schemaFolder the folder where to search for schemas.
     * @throws ApplicationException if no schema is declared in the XML file.
     * @see #validateXmlAgainstSchema(File, URL)
     */
    public static void validateXml(final File xmlFile, final File schemaFolder) {

        final URL schemaUrl = XmlSchemaUtils.extractSchemaUrl(xmlFile, schemaFolder);

        // schema location is defined in XML ?
        if (schemaUrl == null) {
            throw new ApplicationException(XmlErrorType.NO_SCHEMA_FOUND, "Cannot find internal schema URL")
                .addContextValue(XmlErrorContext.XML_FILE, xmlFile);
        }

        validateXmlAgainstSchema(xmlFile, schemaUrl);

        logger.info("XML file [{}] is valid against its schema [{}]", xmlFile, schemaUrl);
    }


}