Jackson jsonSchema Generator /Kotlin

Generate JSON schema from your POJOs using Jackson @Annotations.

This project is a quick re-implementation of mbknor-jackson-jsonSchema by @mbknor, in Kotlin (Java 6 compatible, Android compatible).

Why? I wanted to use it in Android. While mbknor-jackson-jsonSchema can easily be modified to target Java 6, the Scala runtime is still quite an overhead.

Gradle (jcenter)

compile 'com.dr:ktjsonschema:1.0.2'

Maven (jcenter)

<dependency>
  <groupId>com.dr</groupId>
  <artifactId>ktjsonschema</artifactId>
  <version>1.0.2</version>
  <type>pom</type>
</dependency>

Highlights

• JSON Schema Draft v4
• Supports polymorphism (@JsonTypeInfo, MixIn, and registerSubtypes()) using JsonSchema's oneOf-feature.
• Supports schema customization using:
  • @JsonSchemaDescription/@JsonPropertyDescription
  • @JsonSchemaFormat
  • @JsonSchemaTitle
  • @JsonSchemaDefault
• Supports many Javax-validation @Annotations
• Works well with Generated GUI's using https://github.com/jdorn/json-editor
  • (Must be configured to use this mode)
• Supports custom class-to-format mapping
• Supports java.lang.Optional and java8.lang.Optional

Status

The translation from the Scala codebase was blind and quick, so some bugs may be present, though I haven't found any (yet).

Example (Java)

    ObjectMapper objectMapper = new ObjectMapper();
    JsonSchemaGenerator jsonSchemaGenerator = new JsonSchemaGenerator(objectMapper);

    // If using JsonSchema to generate HTML5 GUI:
    // JsonSchemaGenerator html5 = new JsonSchemaGenerator(objectMapper, JsonSchemaConfig.getHtml5EnabledSchema() );

    // If you want to configure it manually:
    // JsonSchemaConfig config = new JsonSchemaConfig(...);
    // JsonSchemaGenerator generator = new JsonSchemaGenerator(objectMapper, config);

    JsonNode jsonSchema = jsonSchemaGenerator.generateJsonSchema(YourPOJO.class);

    String jsonSchemaAsString = objectMapper.writeValueAsString(jsonSchema);