Retrofit 2 Converter for Bean Validation

Overview

This library enables validating beans with Bean Validation using Retrofit 2 thanks to its converter feature.

Getting started

Add dependency

With Maven :

<dependency>
    <groupId>io.github.ghusta.retrofit2</groupId>
    <artifactId>retrofit-converter-validation</artifactId>
    <version>1.0.0</version>
</dependency>

Configure Retrofit and add converters

For example :

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.github.com/")
    .addConverterFactory(ValidationConverterFactory.create())
    .addConverterFactory(GsonConverterFactory.create())
    .build();

Note	The declaration order of converters is important. ValidationConverterFactory must be declared before JSON converters.

Use Annotations

• On DTO (@NotNull, @Size, @Max, etc.)

• On API method parameters (@Valid, before @Body)

• Add @ValidationGroups(groups = {…​}) for specific validation

References

• https://square.github.io/retrofit/

• Jakarta Bean Validation 2.0

• https://futurestud.io/tutorials/retrofit-2-implementing-custom-converters

• https://futurestud.io/tutorials/retrofit-2-introduction-to-multiple-converters

• https://stackoverflow.com/questions/tagged/retrofit