Retrofit post api with multipart list

Question

As we can send list of Request body to api call in retrofit like below

@POST("task/updatedropoff")
    @Multipart
    fun taskUpdateDropOff(
        @Header("apikey") token: String,
        @PartMap user: HashMap<String, RequestBody>,
        @Part image1: MultipartBody.Part? = null,
    ): Call<BaseClass<String>>?

How can we send the list of Parts same as the list of Request body?

I have searched it in retrofit library, android and stack but to no solution.

Answer 1

You can use @Part List<MultipartBody.Part> to send a list of parts. Each part of the list can represent different files or data. The key is constructing a list of MultipartBody.Part objects for each item you want to send.

Here is an example below how you can upload it.

interface ApiService {
    @Multipart
    @POST("upload")
    suspend fun uploadFiles(
        @Part files: List<MultipartBody.Part>
    ): Response<ResponseBody>
}

for creating list:

fun createMultipartList(fileUris: List<Uri>, context: Context): List<MultipartBody.Part> {
    val parts = mutableListOf<MultipartBody.Part>()
    
    fileUris.forEach { uri ->
        val file = File(uri.path)
        val requestBody = file.asRequestBody("multipart/form-data".toMediaTypeOrNull())
        val part = MultipartBody.Part.createFormData("file", file.name, requestBody)
        parts.add(part)
    }
    
    return parts
}