ObjectMapper Factory

The Jackson utility class provides factory methods for creating pre-configured ObjectMapper instances optimized for Dropwizard applications.

Static Factory Methods

newObjectMapper()

Creates a new ObjectMapper with comprehensive Dropwizard configuration including all modules and optimizations.

public static ObjectMapper newObjectMapper()

Returns: Fully configured ObjectMapper instance

Configuration includes:

• Guava module for Guava collections support
• GuavaExtrasModule for CacheBuilderSpec serialization
• CaffeineModule for CaffeineSpec serialization
• FuzzyEnumModule for permissive enum deserialization
• ParameterNamesModule for constructor parameter name preservation
• Jdk8Module for Optional and Stream support
• JavaTimeModule for JSR-310 time types
• Performance module (Afterburner or Blackbird)
• AnnotationSensitivePropertyNamingStrategy for snake_case support
• DiscoverableSubtypeResolver for polymorphic configurations
• Disables FAIL_ON_UNKNOWN_PROPERTIES

Usage Example:

ObjectMapper mapper = Jackson.newObjectMapper();

// The mapper is now ready for production use with all optimizations
String json = mapper.writeValueAsString(complexObject);
MyClass result = mapper.readValue(json, MyClass.class);

newObjectMapper(JsonFactory)

Creates a new ObjectMapper with a custom JsonFactory and full Dropwizard configuration.

public static ObjectMapper newObjectMapper(JsonFactory jsonFactory)

Parameters:

• jsonFactory (JsonFactory, nullable): Custom JsonFactory instance to use

Returns: Fully configured ObjectMapper instance using the provided JsonFactory

Usage Example:

// Create ObjectMapper with custom JsonFactory for YAML processing
YAMLFactory yamlFactory = new YAMLFactory();
ObjectMapper yamlMapper = Jackson.newObjectMapper(yamlFactory);

// Or with custom JSON factory settings
JsonFactory customFactory = new JsonFactory()
    .enable(JsonParser.Feature.ALLOW_COMMENTS);
ObjectMapper mapper = Jackson.newObjectMapper(customFactory);

newMinimalObjectMapper()

Creates a minimal ObjectMapper with only essential Dropwizard configuration for less aggressive processing.

public static ObjectMapper newMinimalObjectMapper()

Returns: Minimally configured ObjectMapper instance

Configuration includes:

• GuavaModule for basic Guava collections support
• DiscoverableSubtypeResolver for polymorphic configurations
• Disables FAIL_ON_UNKNOWN_PROPERTIES

Usage Example:

// Use when the full configuration is too aggressive for your use case
ObjectMapper minimalMapper = Jackson.newMinimalObjectMapper();

// Still provides essential Dropwizard functionality
String json = minimalMapper.writeValueAsString(simpleObject);

Configuration Details

Automatic Module Discovery

The factory methods automatically discover and register Jackson modules available on the classpath:

• Afterburner Module: High-performance bytecode generation (preferred)
• Blackbird Module: Fallback performance enhancement when Afterburner unavailable

Property Handling

• Unknown Properties: Ignored by default (FAIL_ON_UNKNOWN_PROPERTIES disabled)
• Naming Strategy: Supports both camelCase and snake_case via @JsonSnakeCase annotation
• Parameter Names: Preserved in JSON for constructor parameters

Type Support

• Java 8 Types: Optional, Stream, LocalDate, LocalDateTime, Instant, etc.
• Guava Collections: ImmutableList, ImmutableMap, Multimap, etc.
• Cache Specifications: CaffeineSpec and CacheBuilderSpec serialization
• Enums: Fuzzy matching (case-insensitive, handles dashes/periods)