1、引入maven 包

<dependency>
  <groupId>com.squareup.okhttp3</groupId>
   <artifactId>okhttp</artifactId>
   <version>3.9.0</version>
</dependency>

2、编写kotlin代码

import okhttp3.*
import java.io.IOException

fun getDataByGet(): Int {
    try {
        val client = OkHttpClient()
        val request = Request.Builder().get()
            .url("https://www.baidu.com")
            .build()

        val response = client.newCall(request)
        var call = client.newCall(request)
        //异步请求
        call.enqueue(object : Callback {
            override fun onFailure(call: Call, e: IOException) {
                //Log.d("UPDATE", "onFailure: $e")
                println("onFailure: $e")
            }

            @Throws(IOException::class)
            override fun onResponse(call: Call, response: Response) {
                //Log.d("UPDATE", "OnResponse: " + response.body()?.string())
                println("{ $response.body()?.string()}")
            }
        })
    }catch (e:Exception) {
        //Log.e("UPDATE ERROR:", "", e)
    }
    return 1;
}

fun main(){
    println(getDataByGet())
}

3、运行结果

异步调用先返回值

okhttp3的使用_kotlin