islanderman/jackson-modules-java8

Overview

This is a multi-module umbrella project for Jackson
modules needed to support Java 8 features, especially with Jackson 2.x that only
requires Java 7 for running (and until 2.7 only Java 6).

For Jackson 2.x this includes 3 modules:

• Parameter names: support for detecting constructor and factory method ("creator") parameters without having to use @JsonProperty annotation
  • provides com.fasterxml.jackson.module.paramnames.ParameterNamesModule
• Java 8 Date/time: support for Java 8 date/time types (specified in JSR-310 specification)
  • provides com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
  • ALSO provides legacy variant com.fasterxml.jackson.datatype.jsr310.JSR310TimeModule
  • difference between 2 modules is that of configuration defaults: use of JavaTimeModule strongly recommended for new code
• Java 8 Datatypes: support for other new Java 8 datatypes outside of date/time: most notably Optional, OptionalLong, OptionalDouble
  • provides com.fasterxml.jackson.datatype.jdk8.Jdk8Module

all of which are built from this repository, and accessed and used as separate Jackson modules
(with separate Maven artifacts).

Jackson 3.x changes things as it requires Java 8 to work and can thereby directly supported features.
Because of this parameter-names and datatypes modules are merged into jackson-databind
and need not be registered; datetime module (JavaTimeModule) remains separate module due to its size
and configurability options.

License

All modules are licensed under Apache License 2.0.

Status

Usage

Maven dependencies

To include modules, you use some or all of:

<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-parameter-names</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jdk8</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

and either include versions directly, OR, preferably, import
Jackson BOM that will specify consistent version set.

Note that the parent project -- jackson-modules-java8 -- is ONLY used as parent pom by
individual "child" modules, and DOES NOT have dependencies on them. This means that you should not depend on it
as that will not include child modules.

Registering modules

ObjectMapper mapper = new ObjectMapper()
   .registerModule(new ParameterNamesModule())
   .registerModule(new Jdk8Module())
   .registerModule(new JavaTimeModule()); // new module, NOT JSR310Module

or, alternatively, you can also auto-discover these modules with:

ObjectMapper mapper = new ObjectMapper();
mapper.findAndRegisterModules();

Either way, after registration all functionality is available for all normal Jackson operations.

WARNING - As of Jackson 2.x, auto-registration will only register older JSR310Module, and not newer
JavaTimeModule -- this is due to backwards compatibility. Because of this make sure to either use explicit
registration, or, if you want to use JavaTimeModule but also auto-registration, make sure to
register JavaTimeModule BEFORE calling mapper.findAndRegisterModules()).

More

See Wiki for more information (javadocs).