jooby: jackson module

1. Jackson

JSON support using Jackson library.

1.1. Usage

1) Add the dependency:

Maven

Gradle

<dependency>
  <groupId>io.jooby</groupId>
  <artifactId>jooby-jackson</artifactId>
  <version>3.5.5</version>
</dependency>

implementation 'io.jooby:jooby-jackson:3.5.5'

2) Install and encode/decode JSON

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  install(new JacksonModule());                     (1)

  get("/", ctx -> {
    MyObject myObject = ...;
    return myObject;                                (2)
  });

  post("/", ctx -> {
    MyObject myObject = ctx.body(MyObject.class);   (3)
    ...
  });
}

import io.jooby.json.JacksonModule;

{
  install(JacksonModule())                          (1)

  get("/") {
    val myObject = ...;
    myObject                                        (2)
  }

  post("/") {
    val myObject = ctx.body<MyObject>()             (3)
    ...
  }
}

1	Install Jackson
2	Use Jackson to encode arbitrary object as JSON
3	Use Jackson to decode JSON to Java object. Client must specify the `Content-Type: application/json` header

1.2. Working with ObjectMapper

Access to default object mapper is available via require call:

Default object mapper

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  install(new JacksonModule());

  ObjectMapper mapper = require(ObjectMapper.class);

  ...
}

import io.jooby.json.JacksonModule

{
  install(JacksonModule())

  val mapper = require<ObjectMapper>()
}

You can provide your own ObjectMapper:

Custom ObjectMapper

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  ObjectMapper mapper = new ObjectMapper();

  install(new JacksonModule(mapper));
}

import io.jooby.json.JacksonModule

{
  val mapper = ObjectMapper()

  install(JacksonModule(mapper))
}

This allows to configure JacksonModule for doing xml processing:

XmlMapper

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  install(new JacksonModule(new XmlMapper()));
}

import io.jooby.json.JacksonModule

{
  install(JacksonModule(XmlMapper()))
}

If you want jackson and xml processing then install twice:

XmlMapper

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  install(new JacksonModule(new ObjectMapper()));
  install(new JacksonModule(new XmlMapper()));
}

import io.jooby.json.JacksonModule

{
  install(JacksonModule(ObjectMapper()))
  install(JacksonModule(XmlMapper()))
}

1.3. Provisioning Jackson Modules

Jackson module can be provided by a dependency injection framework.

Provisioning Modules

Java

Kotlin

import io.jooby.json.JacksonModule;

{
  install(new JacksonModule().module(MyModule.class);
}

import io.jooby.json.JacksonModule

{
  install(JacksonModule().module(MyModule::class.java)
}

At startup time Jooby ask to dependency injection framework to provide a MyModule instance.