Form Encoder

This module adds support for encoding application/x-www-form-urlencoded and multipart/form-data forms.

Add dependency

Include the dependency to your project's pom.xml file:

<dependencies>
    ...
    <dependency>
        <groupId>io.github.openfeign.form</groupId>
        <artifactId>feign-form</artifactId>
        <version>2.1.0</version>
    </dependency>
    ...
</dependencies>

Usage

Add FormEncoder to your Feign.Builder like so:

SomeApi github = Feign.builder()
                     .encoder(new FormEncoder())
                     .target(SomeApi.class, "http://api.some.org");

Moreover, you can decorate the existing encoder, for example JsonEncoder like this:

SomeApi github = Feign.builder()
                     .encoder(new FormEncoder(new JacksonEncoder()))
                     .target(SomeApi.class, "http://api.some.org");

And use them together:

interface SomeApi {

    @RequestLine("POST /json")
    @Headers("Content-Type: application/json")
    void json (Dto dto);

    @RequestLine("POST /form")
    @Headers("Content-Type: application/x-www-form-urlencoded")
    void from (@Param("field1") String field1, @Param("field2") String field2);

}

You can specify two types of encoding forms by Content-Type header.

application/x-www-form-urlencoded

interface SomeApi {

    ...

    @RequestLine("POST /authorization")
    @Headers("Content-Type: application/x-www-form-urlencoded")
    void authorization (@Param("email") String email, @Param("password") String password);

    ...

}

multipart/form-data

interface SomeApi {

    ...

    @RequestLine("POST /send_photo")
    @Headers("Content-Type: multipart/form-data")
    void sendPhoto (@Param("is_public") Boolean isPublic, @Param("photo") File photo);

    ...

}

In example above, we send file in parameter named photo with additional field in form is_public.

IMPORTANT: You can specify your files in API method by declaring type File or byte[].

Spring MultipartFile and Spring Cloud Netflix @FeignClient support

You can also use Form Encoder with Spring MultipartFile and @FeignClient.

Include the dependencies to your project's pom.xml file:

<dependencies>
    ...
    <dependency>
        <groupId>io.github.openfeign.form</groupId>
        <artifactId>feign-form</artifactId>
        <version>2.1.0</version>
    </dependency>
    <dependency>
        <groupId>io.github.openfeign.form</groupId>
        <artifactId>feign-form-spring</artifactId>
        <version>2.1.0</version>
    </dependency>
    ...
</dependencies>

@FeignClient(name = "file-upload-service", configuration = FileUploadServiceClient.MultipartSupportConfig.class)
public interface FileUploadServiceClient extends IFileUploadServiceClient {

    @Configuration
    public class MultipartSupportConfig {

        @Bean
        @Primary
        @Scope("prototype")
        public Encoder feignFormEncoder() {
            return new SpringFormEncoder();
        }
    }
}