Common XML

This library contains

some xml adapters (for java.util.Date, java.time.Duration, java.time.Instant, java.time.OffsetDateTime etc.),
a pojo to describe a xml model (JaxbContextData) with package or class and schema location,
a provider (JaxbContextDataProvider) of these descriptions that may be loaded with java.util.ServiceLoader into
a JAXB context builder (JaxbContextBuilder) which is able to generate a JAXB context on runtime,
a schema builder (SchemaBuilder)
and a xml document builder (XmlDocumentBuilder).

Usage of JaxbContextBuilder

XML model in packages

For example, there is an extensive xml model that has been generated from many xsd files, like my GPX and Garmin model, and you want to support them in your application.

All the packages which contain the model of the xsd files are described with JaxbContextData and are summed up in an implementation of JaxbContextDataProvider (see for example GarminJaxbContextDataProvider).

The implementation of the provider will be announced to the service loader by a service description.

Then it is very easy to generate the JAXBContext using the JaxbContextBuilder:

import java.util.ServiceLoader;
import javax.xml.bind.JAXBContext;

public class Example {

  public static void main(String[] args) {
    JAXBContext jaxbContext = JaxbContextBuilder
        .newInstance()
        .processAll(ServiceLoader.load(JaxbContextDataProvider.class))
        .buildJaxbContext();
  }
}

Another advantage of using JaxbContextData is the possibility to add a schema location to a xml model that was generated with a xjc maven plugin, because the generated package-info.java files don't have information about the schema location, and I haven't found a way to add the schema location during generation.

If such provider is not present, it is possible to add the packages in different ways and combine them:

import javax.xml.bind.JAXBContext;

public class Example {

  public static void main(String[] args) {
    JAXBContext jaxbContext = JaxbContextBuilder
        .newInstance()
        .add("org.example.model.foo:org.example.model.bar")
        .add(new JaxbContextData("org.example.model.foobar"))
        .buildJaxbContext();
  }
}

Important is that the packages, which contain the model, have a package-info.java annotated with @javax.xml.bind.annotation.XmlSchema and an ObjectFactory.java class. Packages that were generated with XJC normally have these.

Single model class

The JaxbContextBuilder also supports model classes, which are not organized in a package. They only have to be annotated with @XmlRootElement:

import javax.xml.bind.JAXBContext;
import javax.xml.bind.annotation.XmlRootElement;

public class Example {
  
  @XmlRootElement
  public static class Model {
    
    private String value;

    public String getValue() {
      return value;
    }

    public void setValue(String value) {
      this.value = value;
    }
  }

  public static void main(String[] args) {
    JAXBContext jaxbContext = JaxbContextBuilder
        .newInstance()
        .buildJaxbContext(Model.class);
  }
}

Dependency resolving

So far it's not very amazing, the builder just wraps the factory methods of the JAXBContext. Let's go back to the idea that there is an extensive xml model that has been generated from many xsd files. If you marshal an object with that extensive jaxb context, you will get plenty of unnecessary name space declarations and schema locations.

import java.io.StringWriter;
import java.util.ServiceLoader;
import javax.xml.bind.JAXBException;
import org.bremersee.garmin.gpx.v3.model.ext.DisplayColorT;
import org.bremersee.garmin.gpx.v3.model.ext.TrackExtension;
import org.bremersee.xml.JaxbContextBuilder;
import org.bremersee.xml.JaxbContextDataProvider;

public class Example {

  public static void main(String[] args) throws JAXBException {
    TrackExtension model = new TrackExtension();
    model.setDisplayColor(DisplayColorT.CYAN);

    StringWriter sw = new StringWriter();
    JaxbContextBuilder.newInstance()
        .withFormattedOutput(true)
        .processAll(ServiceLoader.load(JaxbContextDataProvider.class))
        .buildMarshaller() // builds a marshaller with the whole jaxb context
        .marshal(model, sw);
    System.out.println(sw);
  }
}

The generated xml may look like this (the declaration is over 9000 characters long):

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns30:TrackExtension xsi:schemaLocation="http://www.garmin.com/xmlschemas/AccelerationExtension/v1 http://bremersee.github.io/xmlschemas/garmin/AccelerationExtensionv1.xsd http://www.garmin.com/xmlschemas/ActiveItemExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/ActiveItemExtensionv1.xsd http://www.garmin.com/xmlschemas/ActivityExtension/v1 http://bremersee.github.io/xmlschemas/garmin/ActivityExtensionv1.xsd http://www.garmin.com/xmlschemas/ActivityExtension/v2 http://bremersee.github.io/xmlschemas/garmin/ActivityExtensionv2.xsd http://www.garmin.com/xmlschemas/ActivityGoals/v1 http://bremersee.github.io/xmlschemas/garmin/ActivityGoalsExtensionv1.xsd http://www.garmin.com/xmlschemas/AdventuresExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/AdventuresExtensionv1.xsd http://www.garmin.com/xmlschemas/CalorieBurnData/v1 http://bremersee.github.io/xmlschemas/garmin/CalorieBurnDataV1.xsd http://www.garmin.com/xmlschemas/ClientProfile/v1 http://bremersee.github.io/xmlschemas/garmin/clientprofilev1.xsd http://www.garmin.com/xmlschemas/ConverterPlugin/v1 http://bremersee.github.io/xmlschemas/garmin/ConverterPluginv1.xsd http://www.garmin.com/xmlschemas/CourseExtension/v1 http://bremersee.github.io/xmlschemas/garmin/CourseExtensionv1.xsd http://www.garmin.com/xmlschemas/CreationTimeExtension/v1 http://bremersee.github.io/xmlschemas/garmin/CreationTimeExtensionv1.xsd http://www.garmin.com/xmlschemas/DeviceDownload/v1 http://bremersee.github.io/xmlschemas/garmin/DeviceDownloadV1.xsd http://www.garmin.com/xmlschemas/DirectoryListing/v1 http://bremersee.github.io/xmlschemas/garmin/DirectoryListingV1.xsd http://www.garmin.com/xmlschemas/Eula/v1 http://bremersee.github.io/xmlschemas/garmin/Eulav1.xsd http://www.garmin.com/xmlschemas/FatCalories/v1 http://bremersee.github.io/xmlschemas/garmin/fatcalorieextensionv1.xsd http://www.garmin.com/xmlschemas/FitnessDeviceLimits/v1 http://bremersee.github.io/xmlschemas/garmin/FitnessDeviceLimitsv1.xsd http://www.garmin.com/xmlschemas/ForerunnerLogbook http://bremersee.github.io/xmlschemas/garmin/ForerunnerLogbookv1.xsd http://www.garmin.com/xmlschemas/GarminDevice/v1 http://bremersee.github.io/xmlschemas/garmin/GarminDevicev1.xsd http://www.garmin.com/xmlschemas/GarminDevice/v2 http://bremersee.github.io/xmlschemas/garmin/GarminDevicev2.xsd http://www.garmin.com/xmlschemas/GarminDeviceExtensions/DataTypeLocation/v1 http://bremersee.github.io/xmlschemas/garmin/DataTypeLocationExtension1.xsd http://www.garmin.com/xmlschemas/GarminDeviceExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/GarminDeviceExtensionv1.xsd http://www.garmin.com/xmlschemas/GarminDeviceExtensions/v2 http://bremersee.github.io/xmlschemas/garmin/GarminDeviceExtensionv2.xsd http://www.garmin.com/xmlschemas/GarminMobileAppPathExtension/v1 http://bremersee.github.io/xmlschemas/garmin/GarminMobileAppPathExtensionv1.xsd http://www.garmin.com/xmlschemas/GarminOEMDeviceExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/GarminOEMDeviceExtensionv1.xsd http://www.garmin.com/xmlschemas/GarminTextTranslation/v1 http://bremersee.github.io/xmlschemas/garmin/GarminTextTranslationv1.xsd http://www.garmin.com/xmlschemas/ggz/1/0 http://bremersee.github.io/xmlschemas/garmin/ggz.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/GpxExtensionsv1.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v2 http://bremersee.github.io/xmlschemas/garmin/GpxExtensionsv2.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v3 http://bremersee.github.io/xmlschemas/garmin/GpxExtensionsv3.xsd http://www.garmin.com/xmlschemas/HardwareVersionExtension/v1 http://bremersee.github.io/xmlschemas/garmin/HardwareVersionExtensionv1.xsd http://www.garmin.com/xmlschemas/HistoryDatabase/v1 http://bremersee.github.io/xmlschemas/garmin/HistoryDatabasev1.xsd http://www.garmin.com/xmlschemas/iFixExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/iFixExtensionv1.xsd http://www.garmin.com/xmlschemas/MobileExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/MobileExtensionv1.xsd http://www.garmin.com/xmlschemas/PressureExtension/v1 http://bremersee.github.io/xmlschemas/garmin/PressureExtensionv1.xsd http://www.garmin.com/xmlschemas/ProfileExtension/v1 http://bremersee.github.io/xmlschemas/garmin/UserProfilePowerExtensionv1.xsd http://www.garmin.com/xmlschemas/TrackPointExtension/v1 http://bremersee.github.io/xmlschemas/garmin/TrackPointExtensionv1.xsd http://www.garmin.com/xmlschemas/TrackPointExtension/v2 http://bremersee.github.io/xmlschemas/garmin/TrackPointExtensionv2.xsd http://www.garmin.com/xmlschemas/TrackStatsExtension/v1 http://bremersee.github.io/xmlschemas/garmin/TrackStatsExtension.xsd http://www.garmin.com/xmlschemas/TripExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/TripExtensionsv1.xsd http://www.garmin.com/xmlschemas/TripMetaDataExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/TripMetaDataExtensionsv1.xsd http://www.garmin.com/xmlschemas/UserAccounts/v1 http://bremersee.github.io/xmlschemas/garmin/UserAccountsExtensionv1.xsd http://www.garmin.com/xmlschemas/UserProfile/v1 http://bremersee.github.io/xmlschemas/garmin/UserProfileExtensionv1.xsd http://www.garmin.com/xmlschemas/UserProfile/v2 http://bremersee.github.io/xmlschemas/garmin/UserProfileExtensionv2.xsd http://www.garmin.com/xmlschemas/ViaPointTransportationModeExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/ViaPointTransportationModeExtensionsv1.xsd http://www.garmin.com/xmlschemas/VideoExtension/v1 http://bremersee.github.io/xmlschemas/garmin/VideoExtensionv1.xsd http://www.garmin.com/xmlschemas/WaypointExtension/v1 http://bremersee.github.io/xmlschemas/garmin/WaypointExtensionv1.xsd http://www.garmin.com/xmlschemas/WebLinkExtensions/v1 http://bremersee.github.io/xmlschemas/garmin/WebLinkExtensionsv1.xsd http://www.garmin.com/xmlschemas/WorkoutDatabase/v1 http://bremersee.github.io/xmlschemas/garmin/WorkoutDatabasev1.xsd http://www.garmin.com/xmlschemas/WorkoutExtension/v1 http://bremersee.github.io/xmlschemas/garmin/WorkoutExtensionv1.xsd http://www8.garmin.com/xmlschemas/FlightPlan/v1 http://bremersee.github.io/xmlschemas/garmin/FlightPlanv1.xsd" xmlns="http://www.garmin.com/xmlschemas/AccelerationExtension/v1" xmlns:ns2="http://www.garmin.com/xmlschemas/ActiveItemExtensions/v1" xmlns:ns4="http://www.garmin.com/xmlschemas/ActivityExtension/v2" xmlns:ns3="http://www.garmin.com/xmlschemas/ActivityExtension/v1" xmlns:ns6="http://www.garmin.com/xmlschemas/AdventuresExtensions/v1" xmlns:ns5="http://www.garmin.com/xmlschemas/ActivityGoals/v1" xmlns:ns8="http://www.garmin.com/xmlschemas/ClientProfile/v1" xmlns:ns51="http://www.garmin.com/xmlschemas/PowerExtension/v1" xmlns:ns7="http://www.garmin.com/xmlschemas/CalorieBurnData/v1" xmlns:ns50="http://www.garmin.com/xmlschemas/WorkoutExtension/v1" xmlns:ns13="http://www.garmin.com/xmlschemas/DeviceDownload/v1" xmlns:ns9="http://www.garmin.com/xmlschemas/ConverterPlugin/v1" xmlns:ns12="http://www.garmin.com/xmlschemas/GarminDeviceExtensions/DataTypeLocation/v1" xmlns:ns11="http://www.garmin.com/xmlschemas/CreationTimeExtension/v1" xmlns:ns10="http://www.garmin.com/xmlschemas/CourseExtension/v1" xmlns:ns17="http://www.garmin.com/xmlschemas/FitnessDeviceLimits/v1" xmlns:ns16="http://www.garmin.com/xmlschemas/FatCalories/v1" xmlns:ns15="http://www.garmin.com/xmlschemas/Eula/v1" xmlns:ns14="http://www.garmin.com/xmlschemas/DirectoryListing/v1" xmlns:ns19="http://www.garmin.com/xmlschemas/ForerunnerLogbook" xmlns:ns18="http://www8.garmin.com/xmlschemas/FlightPlan/v1" xmlns:ns42="http://www.garmin.com/xmlschemas/UserProfile/v1" xmlns:ns41="http://www.garmin.com/xmlschemas/UserAccounts/v1" xmlns:ns40="http://www.garmin.com/xmlschemas/TripMetaDataExtensions/v1" xmlns:ns46="http://www.garmin.com/xmlschemas/VideoExtension/v1" xmlns:ns45="http://www.garmin.com/xmlschemas/ViaPointTransportationModeExtensions/v1" xmlns:ns44="http://www.garmin.com/xmlschemas/ProfileExtension/v1" xmlns:ns43="http://www.garmin.com/xmlschemas/UserProfile/v2" xmlns:ns49="http://www.garmin.com/xmlschemas/WorkoutDatabase/v1" xmlns:ns48="http://www.garmin.com/xmlschemas/WebLinkExtensions/v1" xmlns:ns47="http://www.garmin.com/xmlschemas/WaypointExtension/v1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ns31="http://www.garmin.com/xmlschemas/HardwareVersionExtension/v1" xmlns:ns30="http://www.garmin.com/xmlschemas/GpxExtensions/v3" xmlns:ns35="http://www.garmin.com/xmlschemas/PressureExtension/v1" xmlns:ns34="http://www.garmin.com/xmlschemas/MobileExtensions/v1" xmlns:ns33="http://www.garmin.com/xmlschemas/iFixExtensions/v1" xmlns:ns32="http://www.garmin.com/xmlschemas/HistoryDatabase/v1" xmlns:ns39="http://www.garmin.com/xmlschemas/TripExtensions/v1" xmlns:ns38="http://www.garmin.com/xmlschemas/TrackStatsExtension/v1" xmlns:ns37="http://www.garmin.com/xmlschemas/TrackPointExtension/v2" xmlns:ns36="http://www.garmin.com/xmlschemas/TrackPointExtension/v1" xmlns:ns20="http://www.garmin.com/xmlschemas/GarminDevice/v1" xmlns:ns24="http://www.garmin.com/xmlschemas/GarminMobileAppPathExtension/v1" xmlns:ns23="http://www.garmin.com/xmlschemas/GarminDeviceExtensions/v2" xmlns:ns22="http://www.garmin.com/xmlschemas/GarminDevice/v2" xmlns:ns21="http://www.garmin.com/xmlschemas/GarminDeviceExtensions/v1" xmlns:ns28="http://www.garmin.com/xmlschemas/GpxExtensions/v1" xmlns:ns27="http://www.garmin.com/xmlschemas/ggz/1/0" xmlns:ns26="http://www.garmin.com/xmlschemas/GarminTextTranslation/v1" xmlns:ns25="http://www.garmin.com/xmlschemas/GarminOEMDeviceExtensions/v1" xmlns:ns29="http://www.garmin.com/xmlschemas/GpxExtensions/v2">
    <ns30:DisplayColor>Cyan</ns30:DisplayColor>
</ns30:TrackExtension>

But if you call the build marshaller method for the current object, you will get only declarations that are necessary:

import java.io.StringWriter;
import java.util.ServiceLoader;
import javax.xml.bind.JAXBException;
import org.bremersee.garmin.gpx.v3.model.ext.DisplayColorT;
import org.bremersee.garmin.gpx.v3.model.ext.TrackExtension;
import org.bremersee.xml.JaxbContextBuilder;
import org.bremersee.xml.JaxbContextDataProvider;

public class Example {

  public static void main(String[] args) throws JAXBException {
    TrackExtension model = new TrackExtension();
    model.setDisplayColor(DisplayColorT.CYAN);

    StringWriter sw = new StringWriter();
    JaxbContextBuilder.newInstance()
        .withFormattedOutput(true)
        .processAll(ServiceLoader.load(JaxbContextDataProvider.class))
        .buildMarshaller(model) // builds a marshaller with a subset jaxb context
        .marshal(model, sw);
    System.out.println(sw);
  }
}

Then the generated xml looks like this:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<TrackExtension xsi:schemaLocation="http://www.garmin.com/xmlschemas/GpxExtensions/v3 http://bremersee.github.io/xmlschemas/garmin/GpxExtensionsv3.xsd" xmlns="http://www.garmin.com/xmlschemas/GpxExtensions/v3" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <DisplayColor>Cyan</DisplayColor>
</TrackExtension>

That's pretty nice, isn't it?

The JaxbContextBuilder scans the object and creates internally a new JAXBContext with all required packages or classes. Since the creation of a jaxb context is quite expensive, the created contexts will be cached and reused, if a further object scan returns the same result.

This dependency resolving can be turned off by setting the resolver to null:

import java.io.StringWriter;
import java.util.ServiceLoader;
import javax.xml.bind.JAXBException;
import org.bremersee.garmin.gpx.v3.model.ext.DisplayColorT;
import org.bremersee.garmin.gpx.v3.model.ext.TrackExtension;
import org.bremersee.xml.JaxbContextBuilder;
import org.bremersee.xml.JaxbContextDataProvider;

public class Example {

  public static void main(String[] args) throws JAXBException {
    TrackExtension model = new TrackExtension();
    model.setDisplayColor(DisplayColorT.CYAN);

    StringWriter sw = new StringWriter();
    JaxbContextBuilder.newInstance()
        .withFormattedOutput(true)
        .withDependenciesResolver(null) // turns off dependency resolving
        .processAll(ServiceLoader.load(JaxbContextDataProvider.class))
        .buildMarshaller(model)
        .marshal(model, sw);
    System.out.println(sw);
  }
}

Usage of SchemaBuilder

The schema builder wraps the standard SchemaFactory of Java into a builder. It also offers the ability to load schema using Spring's ResourceLoader.

import javax.xml.validation.Schema;

public class Example {

  public static void main(String[] args) {
    Schema schema = SchemaBuilder.newInstance()
        .buildSchema("classpath:common-xml-test-model-1.xsd",
            "http://bremersee.github.io/xmlschemas/common-xml-test-model-7b.xsd");
  }
}

Usage of XmlDocumentBuilder

The xml document builder wraps the functionality of the standard DocumentBuilderFactory and DocumentBuilder of Java into one builder.

It may be useful to create elements for objects that can contain any element:

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.JAXBException;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAnyElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlValue;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class Example {

  @XmlRootElement
  @XmlAccessorType(XmlAccessType.FIELD)
  public static class Model {

    @XmlValue
    private String value;

    public String getValue() {
      return value;
    }

    public void setValue(String value) {
      this.value = value;
    }
  }

  @XmlRootElement
  @XmlAccessorType(XmlAccessType.FIELD)
  public static class ModelContainer {

    @XmlElementWrapper(name = "models")
    @XmlAnyElement
    private List<Element> models;

    public List<Element> getModels() {
      if (models == null) {
        models = new ArrayList<>();
      }
      return models;
    }
  }

  public static void main(String[] args) throws JAXBException {
    Model model = new Model();
    model.setValue("Hello world!");

    Document document = XmlDocumentBuilder.newInstance()
        .buildDocument(model, JaxbContextBuilder.newInstance().buildMarshaller(model));

    ModelContainer container = new ModelContainer();
    container.getModels().add(document.getDocumentElement());

    StringWriter sw = new StringWriter();
    JaxbContextBuilder.newInstance().buildMarshaller(container).marshal(container, sw);
    System.out.println(sw);
  }
}

The xml will be:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<modelContainer>
    <models>
        <model>Hello world!</model>
    </models>
</modelContainer>