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Jackson Module

Project Dependencies

Add the following dependency to your pom.xml/build.gradle file:

implementation("com.raynigon.unit-api:unit-api-jackson:{{latest_version}}")
<dependency>
    <groupId>com.raynigon.unit-api</groupId>
    <artifactId>unit-api-jackson</artifactId>
    <version>{{latest_version}}</version>
</dependency>

Configuration

Options

Feature Default Description
SYSTEM_UNIT_ON_MISSING_ANNOTATION disabled If no Annotation is present and the given input is a number, the system unit for this quantity should be used.

Usage

ObjectMapper mapper = new ObjectMapper()
mapper.registerModule(new UnitApiModule())
UnitApiModule module = UnitApiModule.withFeatures(SYSTEM_UNIT_ON_MISSING_ANNOTATION)

Examples

You can declare your model like this:

class ExampleEntity {

    public String id;

    @JsonUnit(KilometrePerHour.class)
    public Quantity<Speed> speed;
}

Jackson will now accept any quantity and convert it to the given unit. The following examples will be accepted by Jackson:

{
    "id": "65bf1872-d197-4d72-9950-2b7b4d74a674",
    "speed": 80
}
{
    "id": "65bf1872-d197-4d72-9950-2b7b4d74a674",
    "speed": "80"
}
{
    "id": "65bf1872-d197-4d72-9950-2b7b4d74a674",
    "speed": {
        "value:" 80,
        "unit": "km/h"
    }
}
{
    "id": "65bf1872-d197-4d72-9950-2b7b4d74a674",
    "speed": "80 km/h"
}
{
    "id": "65bf1872-d197-4d72-9950-2b7b4d74a674",
    "speed": "22.2222 m/s"
}

Every example will result in having the speed property with a value of 80 and the unit "km/h".

If you don't want to annotate the Attributes in your class, you can enable the SYSTEM_UNIT_ON_MISSING_ANNOTATION Feature. With this Feature enabled, the Mapper will accept a number and convert it to the given System Unit. (e.g. for speed m/s in the SI-System)