it.bz.opendatahub.alpinebits.xml.JAXBObjectToXmlConverter Maven / Gradle / Ivy
// SPDX-FileCopyrightText: NOI Techpark
//
// SPDX-License-Identifier: MPL-2.0
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
package it.bz.opendatahub.alpinebits.xml;
import it.bz.opendatahub.alpinebits.xml.schema.ota.ObjectFactory;
import org.xml.sax.SAXException;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.Validator;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
/**
* This class provides methods to convert OTA-2015A objects to XML.
*
* Please note, that this class can only be used with OTA-2015A objects
* declared in the {@link ObjectFactory}, since those are the only
*/
public final class JAXBObjectToXmlConverter implements ObjectToXmlConverter {
private final Schema schema;
private final boolean doPrettyPrintXml;
private final Schema otaSchema;
private JAXBObjectToXmlConverter(Schema schema, boolean doPrettyPrintXml) {
this.schema = schema;
this.doPrettyPrintXml = doPrettyPrintXml;
this.otaSchema = XmlValidationSchemaProvider.buildXsdSchema("ota2015a-min.xsd");
}
@Override
public void toXml(Object objectToConvert, OutputStream os) {
try {
Marshaller marshaller = JAXBContextSingleton.getInstance().createMarshaller();
marshaller.setSchema(this.schema);
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, this.doPrettyPrintXml);
// Write XML to temporary string such that it can be reused for OTA 2015a XSD validation
ByteArrayOutputStream tmpStream = new ByteArrayOutputStream();
marshaller.marshal(objectToConvert, tmpStream);
String xml = tmpStream.toString();
// Validate against OTA 2015a XSD
Validator validator = this.otaSchema.newValidator();
validator.validate(toSource(xml));
// Write XML to output stream
os.write(xml.getBytes(StandardCharsets.UTF_8));
} catch (JAXBException | SAXException | IOException e) {
String message = "Object-to-XML conversion error: " + (e.getMessage() == null ? e.toString() : e.getMessage());
throw new XmlConversionException(message, e);
}
}
private Source toSource(String xml) {
return new StreamSource(new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8)));
}
/**
* Builder to create instances of {@link JAXBObjectToXmlConverter}.
*/
public static class Builder {
private Schema schema;
private boolean doPrettyPrintXml;
/**
* The {@link Schema} is used for XML validation.
*
* If the schema is null (default: null), no validation will
* be performed.
*
* @param schema the {@link Schema} used for XML validation
* @return the current Builder
*/
public Builder schema(Schema schema) {
this.schema = schema;
return this;
}
/**
* Configure, if the resulting XML should be pretty printed
* (default: false).
*
* @param doPrettyPrintXml if true, the resuling
* XML will be pretty printed
* @return the current Builder
*/
public Builder prettyPrint(boolean doPrettyPrintXml) {
this.doPrettyPrintXml = doPrettyPrintXml;
return this;
}
/**
* Build an instance of {@link JAXBObjectToXmlConverter} with
* the current configuration.
*
* @return instance of {@link JAXBObjectToXmlConverter}
*/
public ObjectToXmlConverter build() {
return new JAXBObjectToXmlConverter(this.schema, this.doPrettyPrintXml);
}
}
}