java-jsonld-mappings

Library provides easy to use Java classes and builders for schema.org entities.

All classes are auto generated from schemaorg-all-http.rdf (HTTPS version doesn't work)

Usage

Include Maven dependency

<repository>
    <id>jsonld-metadata</id>
    <url>https://raw.github.com/indigobyte/jsonld-metadata/mvn-repo/</url>
    <snapshots>
        <enabled>true</enabled>
    </snapshots>
</repository>

<properties>
    <jsonld-metadata.version>1.0.1</jsonld-metadata.version>
</properties>

<dependencies>
    <dependency>
        <groupId>com.indigobyte</groupId>
        <artifactId>jsonld-metadata</artifactId>
        <version>${jsonld-metadata.version}</version>
    </dependency>
</dependencies>

Use in Java code

import static org.schema.SchemaOrg.*;

final Article article = SchemaOrg.article() // with static import you can skip `SchemaOrg.`, left here for clarity
        .name("88th Oscars ceremony will be held on February 28th")
        .text("Lorem ipsum")
        .author(nGO()
                   .name("The Academy of Motion Picture Arts and Sciences")
                   .build()
        )
        .comment(
                // note that you may provide Builder instead of object where it is unambiguous
                comment()
                .text("Hooray!")
                .author(
                    person()
                        .name("Max Mustermann")
                )
        ).build();

Generate JSON-LD script

Create <script type="application/ld+json"> snippet with Jackson like this:

@NotNull
public static String getJsonLdScript(@NotNull Thing thing) {
    final ObjectMapper mapper = new ObjectMapper();
    mapper.enable(SerializationFeature.INDENT_OUTPUT);
    mapper.getFactory().setCharacterEscapes(new HTMLCharacterEscapes());
    mapper.getFactory().configure(JsonGenerator.Feature.ESCAPE_NON_ASCII, true);
    // Taken from https://www.baeldung.com/jackson-serialize-dates#iso-8601
    mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    // StdDateFormat is ISO8601 since jackson 2.9
    mapper.setDateFormat(new StdDateFormat().withColonInTimeZone(true));
    try {
        try (var writer = new StringWriter()) {
            mapper.writeValue(writer, thing);
            return "<script type=\"application/ld+json\">\n" +
                writer +
                "\n</script>\n";
        }
    } catch (Throwable e) {
        log.error(() -> "Error serializing " + thing, e);
        return "";
    }
}

Editing JSON-LD builder

You can edit (and remove) properties of the builder that were set previously:

final Event.Builder eventBuilder = SchemaOrg.event();
// Let's say that location was added previously
eventBuilder.location(SchemaOrg.place().name("White House").build());
// Now we want to add country and city to this location
final Place.Builder placeBuilder;
if (eventBuilder.getLocation() instanceof Place place) {
    placeBuilder = place.toBuilder(); // If it was already set, then create placeBuilder from existing data
} else {
    placeBuilder = SchemaOrg.place(); // Otherwise create a new placeBuilder instance
}
// Now set the address
placeBuilder.address(SchemaOrg.postalAddress()
    .addressCountry("USA")
    .addressLocality("Washington, DC")
    .build()
);
eventBuilder.removeLocation() // Remove location without address, the one specified previously. If you don't remove it, then eventBuilder will have multiple locations
    .location(placeBuilder.build()); // Set new location, the one with address.

Updating schema.org schema

• Find schema.org schema in RDF format. It must be HTTP schema, not HTTPS!. You can find it at GitHub. Take "all" schema instead of "current" since "current" one uses definitions from "all", and there will be "not found/undefined" errors when using "current" schema instead of "all".
• Replace file generator/resources/schemaorg-all-http.rdf with the new version.
• Delete src/generated and src/generated-test folders.
• Run generator/src/main/kotlin/org/schema/generator/generator.kt's main function. Must set working directory to generator before running. Generated files will be placed in src/generated and src/generated-test.

Building new version

• Update version inside gradle.properties file.
• Build this via gradle clean build
• Checkout mvn-repo branch of this repository into separate folder.
• Create build/mvnRepo folder.
• Put contents of mvn-repo branch of this git repository into build/mvnRepo folder. As the result, you'll get build/mvnRepo/com/indigobyte folder.
• Run gradle :publishJsonLdMetadataPublicationPublicationToMvnRepoRepository
• Commit and push build/mvnRepo folder to mvn-repo git branch.