用Kotlin进行改装，无法创建@Body

Question

Hi i get the following error:

 java.lang.IllegalArgumentException: Unable to create @Body converter for class com.jr.app.models.ExampleData (parameter #1)

Here is my ExampleData.kt

data class ExampleData(val id: String,
                   val firstName: String,
                   val secondName: String,
                   val profilImages: String,
                   val info: String) {

}

My interface retrofit

interface UsersService {

@GET("/usersProfile")
fun getAllUsers(): Call<List<ExampleData>>

@POST("/usersProfile")
fun addUser(@Body exampleData: ExampleData): Call<ResponseBody>

}

function that addsUser

  override fun addUser(user: ExampleData) {
    val retrofit = Retrofit.Builder().baseUrl(baseUrl).client(httpAuthClient).build();
    val userService = retrofit.create(UsersService::class.java);
    userService.addUser(user).enqueue(callbackResponse);
}

 private val httpAuthClient: OkHttpClient
    get() {
        val okHttpClient = OkHttpClient().newBuilder().addInterceptor { chain ->
            val originalRequest = chain.request()

            val builder = originalRequest.newBuilder().header(authorizeHeader,
                    Credentials.basic(userName, password))

            val newRequest = builder.build()
            chain.proceed(newRequest)
        }.build()

        return okHttpClient


}

Answer 1

Add the gradle dependency to your project:

compile 'com.squareup.retrofit2:converter-gson:VERSION_OF_RETROFIT'

When you build an instance of retrofit add this line:

.addConverterFactory(GsonConverterFactory.create())

In your project building the retrofit object will look like:

val retrofit = Retrofit.Builder()
    .baseUrl(baseUrl)
    .client(httpAuthClient)
    .addConverterFactory(GsonConverterFactory.create())
    .build()

Answer 2

I believe this has nothing to do with Kotlin but your Retrofit configuration and your data class ExampleData.

Retrofit has no idea how to serialize your instance of ExampleData to JSON. You need to add a specific converter factory when creating instance of Retrofit client (see Builder#addConverterFactory method for details).