注意：在android6.0以后网络请求还需如下配置：

 android:usesCleartextTraffic="true"

<applicationandroid:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:roundIcon="@mipmap/ic_launcher_round"android:supportsRtl="true"android:usesCleartextTraffic="true"android:theme="@style/AppTheme">***
</application>

一、引入okhttp3包

 //okhttp3implementation("com.squareup.okhttp3:okhttp:4.9.0")implementation("com.squareup.okhttp3:logging-interceptor:4.9.0")

二、创建单例对象

package com.example.buju.httpimport android.content.Context
import android.os.Environment
import android.util.Log
import android.widget.Toast
import okhttp3.Call
import okhttp3.Callback
import okhttp3.FormBody
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.MultipartBody
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.RequestBody
import okhttp3.Response
import org.json.JSONObject
import java.io.File
import java.io.IOException
import java.util.concurrent.TimeUnit
/*** 单例对象*  -http请求工具类* */
object HiOkhttp {/*  private val client:OkHttpClient// 最早调用模块init {val httpLoggingInterceptor = HttpLoggingInterceptor()// okhttp3自带拦截器httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY)client = OkHttpClient.Builder()// builder构造者设计模式.connectTimeout(10,TimeUnit.SECONDS)//连接超时时间.readTimeout(10,TimeUnit.SECONDS)// 读取超时.writeTimeout(10,TimeUnit.SECONDS)// 写超时.addInterceptor(httpLoggingInterceptor)// 自带拦截器.build()}*/val client = OkHttpClient.Builder()// builder构造者设计模式.connectTimeout(10,TimeUnit.SECONDS)//连接超时时间.readTimeout(10,TimeUnit.SECONDS)// 读取超时.writeTimeout(10,TimeUnit.SECONDS)// 写超时.addInterceptor(LoggingInterceptor())// 自定义拦截器.build()// android 分为主线程和子线程// 主线程就是APP一启动后，咱们android framework层会启动一个线程，主线程（UI线程）// 子线程 - new Thread().start()/*** get请求*  -同步请求不要放在主线程中执行，容易阻塞线程* */fun syncGet(url:String){// 构造请求体val request:Request = Request.Builder().url(url).build()// 构造请求对象val call:Call = client.newCall(request)Thread(Runnable {// 构建子线程// execute() - 发起同步请求（同步执行）val  response:Response = call.execute()val body: String? = response.body?.string()Log.e("OKHTTP","get response:${body}")}).start()}/*** get请求*  -异步请求* */fun asyncGet(url:String){// 构造请求体val request:Request = Request.Builder().url(url).build()// 构造请求对象val call:Call = client.newCall(request)// enqueue() - 发起异步请求（异步执行）call.enqueue(object :Callback{override fun onFailure(call: Call, e: IOException) {Log.e("OKHTTP","get onFailure:${e.message}")}override fun onResponse(call: Call, response: Response) {val body:String? = response.body?.string()Log.e("OKHTTP","get response:${body}")}})}/*** post请求*  -同步表单请求，不要放在主线程中执行，容易阻塞线程* */fun syncPost(url:String){val body = FormBody.Builder().add("userId","123").add("userName","zs").build()val request:Request = Request.Builder().url(url).post(body).build()val call:Call = client.newCall(request)Thread(Runnable {val response:Response = call.execute()val resultBody = response.body?.string()Log.e("OKHTTP","post response:${resultBody}")}).start()}/*** post请求*  -异步表单请求* */fun asyncPost(url:String){val body = FormBody.Builder().add("userId","123").add("userName","zs").build()val request:Request = Request.Builder().url(url).post(body).build()val call:Call = client.newCall(request)call.enqueue(object :Callback{override fun onFailure(call: Call, e: IOException) {Log.e("OKHTTP","post onFailure:${e.message}")}override fun onResponse(call: Call, response: Response) {val resultBody = response.body?.string()Log.e("OKHTTP","post response:${resultBody}")}})}/*** post请求*  -异步多表单文件上传请求*  -url必须支持文件上传的接口*  -android6.0以后，读取外部存储卡的文件都是需要动态申请权限* */fun asyncPostMultipart(url:String,context:Context){val file = File(Environment.getExternalStorageDirectory(),"demo.png")if (!file.exists()){Toast.makeText(context,"文件不存在",Toast.LENGTH_LONG).show()return}val body = MultipartBody.Builder().addFormDataPart("key1","value1").addFormDataPart("key2","value2").addFormDataPart("file","file.png",RequestBody.create("application/octet-stream".toMediaType(), file)).build()val request:Request = Request.Builder().url(url).post(body).build()val call:Call = client.newCall(request)call.enqueue(object :Callback{override fun onFailure(call: Call, e: IOException) {Log.e("OKHTTP","post onFailure:${e.message}")}override fun onResponse(call: Call, response: Response) {val resultBody = response.body?.string()Log.e("OKHTTP","post response:${resultBody}")}})}/*** post请求*  -异步字符串请求* */fun asyncPostString(url:String){// 纯文本/* val textPlain = "text/plain;charset=utf-8".toMediaType()val textObj = "username:username;password:1234"val body = RequestBody.create(textPlain,textObj)*/// json对象val applicationJson = "application/json;charset=utf-8".toMediaType();val jsonObj = JSONObject()jsonObj.put("key1","val1")jsonObj.put("key2","val2")val body = RequestBody.create(applicationJson,jsonObj.toString())val request = Request.Builder().url(url).post(body).build()val call:Call = client.newCall(request)call.enqueue(object :Callback{override fun onFailure(call: Call, e: IOException) {Log.e("OKHTTP","post onFailure:${e.message}")}override fun onResponse(call: Call, response: Response) {val resultBody = response.body?.string()Log.e("OKHTTP","post response:${resultBody}")}})}}

三、自定义okhttp3拦截器

package com.example.buju.httpimport android.util.Log
import okhttp3.Interceptor
import okhttp3.Response
import okhttp3.ResponseBody
import okio.Buffer/*** OKHttp3 拦截器* */
class LoggingInterceptor:Interceptor {override fun intercept(chain: Interceptor.Chain): Response {val time_start = System.nanoTime()// 开始时间戳val request = chain.request()// 请求val response = chain.proceed(request)// 响应/*** 获取请求信息* */val buffer = Buffer()// okio.Bufferrequest.body?.writeTo(buffer)val requestBodyStr = buffer.readUtf8()// request.url - 请求接口；requestBodyStr - 请求携带的参数Log.e("OKHTTP",String.format("Sending request %s with params %s",request.url,requestBodyStr))/*** 获取响应信息* */val bussinessData:String = response.body?.string()?:"response body null"val mediaType = response.body?.contentType()val newBody = ResponseBody.create(mediaType,bussinessData)val newResponse = response.newBuilder().body(newBody).build()val time_end = System.nanoTime()//结束始时间戳//  request.url - 请求接口；(time_end - time_start) -执行时间；bussinessData - 响应数据Log.e("OKHTTP",String.format("Received response for %s in %.1fms >>> %s",request.url,(time_end - time_start),bussinessData))return newResponse}}