flutter 直传oss原文更改upload方法，使其null-safety `` /* @Author: jeft

更改upload方法，使其null-safety

`` /*

@Author: jeft
@Date: 2022-02-08 16:52:31
@LastEditTime: 2022-02-08 18:47:00
@LastEditors: Please set LastEditors
@Description: 打开koroFileHeader查看配置进行设置: github.com/OBKoro1/kor…
@FilePath: \duolu_flutter\lib\http\oss_file.dart */ import "dart:convert"; import "dart:io"; import "dart:math"; import "package:crypto/crypto.dart"; import "package:dio/dio.dart";

class UploadOss { static String ossAccessKeyId = "";

static String ossAccessKeySecret = ""; // oss设置的bucket的名字 static String bucket = ""; // 发送请求的url,根据你自己设置的是哪个城市的 static String url = "https://$bucket.oss-cn-shenzhen.aliyuncs.com";

// 过期时间 static String expiration = "2025-01-01T12:00:00.000Z";

// /** // * @params file 要上传的文件对象 // * @params rootDir 阿里云oss设置的根目录文件夹名字 // * @param fileType 文件类型例如jpg,mp4等 // * @param callback 回调函数我这里用于传cancelToken，方便后期关闭请求 // * @param onSendProgress 上传的进度事件 // */

static Future upload(File file, {String rootDir = "moment", String? fileType, Function? callback, Function? onSendProgress}) async { String policyText = '{"expiration": " $expiration","conditions": [{"bucket": "$ bucket" },["content-length-range", 0, 1048576000]]}';

// 获取签名
String signature = getSignature(policyText);

BaseOptions options = new BaseOptions();
options.responseType = ResponseType.plain;

//创建dio对象
Dio dio = new Dio(options);
// 生成oss的路径和文件名我这里目前设置的是moment/20201229/test.mp4
String pathName =
    "$rootDir/${getDate()}/${getRandom(12)}.${fileType == null ? getFileType(file.path) : fileType}";

// 请求参数的form对象
FormData data = new FormData.fromMap({
  "key": pathName,
  "policy": getSplicyBase64(policyText),
  "OSSAccessKeyId": ossAccessKeyId,
  "success_action_status": "200", //让服务端返回200，不然，默认会返回204
  "signature": signature,
  "contentType": "multipart/form-data",
  "file": MultipartFile.fromFileSync(file.path),
});

Response response;
CancelToken uploadCancelToken = CancelToken();
if (callback != null) {
  callback(uploadCancelToken);
}

try {
  // 发送请求
  response = await dio.post(url, data: data, cancelToken: uploadCancelToken,
      onSendProgress: (int count, int data) {
    onSendProgress != null
        ? onSendProgress(count, data)
        : print('---progress-$count--dd-$data');
  });
  // 成功后返回文件访问路径
  return "$url/$pathName";
} catch (e) {
  // throw(e.message);
  return '';
}

}

生成固定长度的随机字符串
*/ static String getRandom(int num) { String alphabet = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM"; String left = ""; for (var i = 0; i < num; i++) { // right = right + (min + (Random().nextInt(max - min))).toString(); left = left + alphabet[Random().nextInt(alphabet.length)]; } return left; }

根据图片本地路径获取图片名称
*/ static String? getImageNameByPath(String filePath) { // ignore: null_aware_before_operator return filePath.substring(filePath.lastIndexOf("/") + 1, filePath.length); }

获取文件类型 */ static String getFileType(String path) { List array = path.split("."); return array[array.length - 1]; }

/// 获取日期 static String getDate() { DateTime now = DateTime.now(); return " ${now.year}$ {now.month}${now.day}"; }

// 获取plice的base64 static getSplicyBase64(String policyText) { //进行utf8编码 List policyText_utf8 = utf8.encode(policyText); //进行base64编码 String policy_base64 = base64.encode(policyText_utf8); return policy_base64; }

/// 获取签名 static String getSignature(String policyText) { //进行utf8编码 List policyText_utf8 = utf8.encode(policyText); //进行base64编码 String policy_base64 = base64.encode(policyText_utf8); //再次进行utf8编码 List policy = utf8.encode(policy_base64); //进行utf8 编码 List key = utf8.encode(ossAccessKeySecret); //通过hmac,使用sha1进行加密 List signature_pre = Hmac(sha1, key).convert(policy).bytes; //最后一步，将上述所得进行base64 编码 String signature = base64.encode(signature_pre); return signature; } }