retrofit - kotlin -指定为非空的参数为空

interface ApiService {
    @GET("example")
    fun getExampleData(@Query("param") param: String?): Call<ExampleResponse>
}

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

val apiService = retrofit.create(ApiService::class.java)

val param: String? = null

apiService.getExampleData(param!!)
    .enqueue(object : Callback<ExampleResponse> {
        override fun onResponse(call: Call<ExampleResponse>, response: Response<ExampleResponse>) {
            // 处理成功响应
        }

        override fun onFailure(call: Call<ExampleResponse>, t: Throwable) {
            // 处理失败响应
        }
    })