public class MainActivity extends AppCompatActivity {  private OkHttpClient client;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    client = new OkHttpClient();    postImage();  }  private void postImage(){    //這里方便演示。讀取drawable里的圖片。    Bitmap bm = BitmapFactory.decodeResource(getResources(),R.drawable.demo);    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();    bm.compress(Bitmap.CompressFormat.JPEG,100,byteArrayOutputStream);    MultipartBody.Builder builder = new MultipartBody.Builder().setType(MultipartBody.FORM)        .addFormDataPart("img_1","1.jpg", RequestBody.create(MediaType.parse("image/jpeg"),byteArrayOutputStream.toByteArray()))        .addFormDataPart("img_2","2.jpg", RequestBody.create(MediaType.parse("image/jpeg"),byteArrayOutputStream.toByteArray()))        ;    //有多個圖片就用for循環添加即可    MultipartBody build = builder.build();    okhttp3.Request bi = new okhttp3.Request.Builder()        .url("后臺地址")         .post(build)        .build();    client.newCall(bi).enqueue(new Callback() {      @Override      public void onFailure(Call call, IOException e) {        Log.i("TAG", "onFailure: 失敗");      }      @Override      public void onResponse(Call call, okhttp3.Response response) throws IOException {        Log.i("TAG", "onResponse: " + response.body().string());        //提交成功處理結果....      }    });  }}

<?phpheader('Content-type: application/json;charset=utf-8');if(empty($_FILES)) die('{"status":0,"msg":"錯誤提交"}');$dirPath = './img/';//設置文件保存的目錄if(!is_dir($dirPath)){  //目錄不存在則創建目錄  @mkdir($dirPath);}$count = count($_FILES);//所有文件數if($count<1) die('{"status":0,"msg":"錯誤提交"}');//沒有提交的文件$success = $failure = 0;foreach($_FILES as $key => $value){  //循環遍歷數據  $tmp = $value['name'];//獲取上傳文件名  $tmpName = $value['tmp_name'];//臨時文件路徑  //上傳的文件會被保存到php臨時目錄，調用函數將文件復制到指定目錄  if(move_uploaded_file($tmpName,$dirPath.date('YmdHis').'_'.$tmp)){    $success++;  }else{    $failure++;  }}$arr['status'] = 1;$arr['msg']   = '提交成功';$arr['success'] = $success;$arr['failure'] = $failure;echo json_encode($arr);