flutter Upload files directly to Alibaba Cloud oss
- 2021-12-13 09:11:11
- OfStack
Directory code implementation
Example of calling upload
Another way to prepare: Give a tool class
Code implementation
Example of calling upload
Another way to prepare: Give a tool class
Code implementation
The following is a class I wrote to upload oss, which can be uploaded directly only by replacing the parameters of ossAccessKeyId, ossAccessKeySecret, bucket, url and expiration
import 'dart:convert';
import 'dart:io';
import 'dart:math';
import 'package:crypto/crypto.dart';
import 'package:dio/dio.dart';
class UploadOss {
static String ossAccessKeyId = 'ossAccessKeyId';
static String ossAccessKeySecret = 'ossAccessKeySecret';
// oss Set bucket The name of
static String bucket = 'bucketName';
// Sending the requested url, According to which city you set it up
static String url = 'https://$bucket.oss-cn-hangzhou.aliyuncs.com';
// Expired time
static String expiration = '2025-01-01T12:00:00.000Z';
/**
* @params file File object to upload
* @params rootDir Alibaba Cloud oss Root folder name set
* @param fileType File types such as jpg,mp4 Etc
* @param callback Callback function I use here to pass cancelToken Which facilitates late closure requests
* @param onSendProgress Uploaded progress events
*/
static Future<String> upload({ File file , String rootDir = 'moment', String fileType, Function callback, Function onSendProgress}) async {
String policyText = '{"expiration": "$expiration","conditions": [{"bucket": "$bucket" },["content-length-range", 0, 1048576000]]}';
// Get a signature
String signature = getSignature(policyText);
BaseOptions options = new BaseOptions();
options.responseType = ResponseType.plain;
// Create dio Object
Dio dio = new Dio(options);
// Generate oss The path and file name I currently set here is moment/20201229/test.mp4
String pathName = '$rootDir/${getDate()}/${getRandom(12)}.${fileType == null ? getFileType(file.path) : fileType}';
// Object of the request parameter form Object
FormData data = new FormData.fromMap({
'key': pathName,
'policy': getSplicyBase64(policyText),
'OSSAccessKeyId': ossAccessKeyId,
'success_action_status': '200', // Let the server return 200 Otherwise, the default returns 204
'signature': signature,
'contentType': 'multipart/form-data',
'file': MultipartFile.fromFileSync(file.path),
});
Response response;
CancelToken uploadCancelToken = CancelToken();
callback ?? callback(uploadCancelToken);
try {
// Send a request
response = await dio.post(url, data: data, cancelToken: uploadCancelToken, onSendProgress: (int count, int data) {
onSendProgress(count, data);
});
// Return to the file access path after success
return '$url/$pathName';
} catch(e) {
throw(e.message);
}
}
/*
* Generate a random string of fixed length
* */
static String getRandom(int num) {
String alphabet = 'qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM';
String left = '';
for (var i = 0; i < num; i++) {
// right = right + (min + (Random().nextInt(max - min))).toString();
left = left + alphabet[Random().nextInt(alphabet.length)];
}
return left;
}
/*
* Get the picture name according to the local path of the picture
* */
static String getImageNameByPath(String filePath) {
// ignore: null_aware_before_operator
return filePath?.substring(filePath?.lastIndexOf("/")+1,filePath?.length);
}
/**
* Get the file type
*/
static String getFileType(String path) {
print(path);
List<String> array = path.split('.');
return array[array.length -1];
}
/// Get Date
static String getDate() {
DateTime now = DateTime.now();
return '${now.year}${now.month}${now.day}';
}
// Get plice Adj. base64
static getSplicyBase64(String policyText) {
// Go on utf8 Code
List<int> policyText_utf8 = utf8.encode(policyText);
// Go on base64 Code
String policy_base64 = base64.encode(policyText_utf8);
return policy_base64;
}
/// Get a signature
static String getSignature(String policyText) {
// Go on utf8 Code
List<int> policyText_utf8 = utf8.encode(policyText);
// Go on base64 Code
String policy_base64 = base64.encode(policyText_utf8);
// Go on again utf8 Code
List<int> policy = utf8.encode(policy_base64);
// Go on utf8 Code
List<int> key = utf8.encode(ossAccessKeySecret);
// Pass hmac, Use sha1 Encrypt
List<int> signature_pre = Hmac(sha1, key).convert(policy).bytes;
// Finally 1 Step of carrying out the above obtained base64 Code
String signature = base64.encode(signature_pre);
return signature;
}
}
Example of calling upload
Other counselors upload them according to their own situation
Future<String> uploadFile(File file, { Function onSendProgress, Function callback}) async {
final String url = await UploadOss.upload(file: file, onSendProgress: onSendProgress, callback: callback);
return url;
}
Another method
At present, Ali does not have an official SDK for Flutter to integrate, but some people upload Flutter with a packaging library https://pub.dev/packages/aly_oss #-example-tab-, so we can only upload it in the form of post submission;
Preparations:
1. Obtain the OSS certificate address (your oss _sts _server), and notify get to directly obtain static String ossServerUrl = 'http://../sts-server/sts. php';
2. Uploaded storage address (bucket name): static String ossEndPointCdn = ' < your endpointcdn > ';
// Pass ossServerUrl Direct get The following data is obtained
{
"StatusCode": 200,
"AccessKeyId": "STS.NSsrKZes4cqm.....",
"AccessKeySecret": "7eGnLZaEFsRCGYJAnrtdE9n.....",
"Expiration": "2020-04-08T03:44:21Z",
"SecurityToken": "CAISlQJ1q6Ft5B2y....."
}
// Parameters required by the form : AccessKeyId , AccessKeySecret , SecurityToken;
FormData formdata = new FormData.from({
// File name, optional
'Filename': OssUtil.instance.getImageName(filePath),
//" You can fill in the folder name (corresponding to the oss Folders in the service) /" + fileName
'key': uploadName,// File name after uploading
'policy': OssUtil.policy,
//Bucket Owner's AccessKeyId .
'OSSAccessKeyId': data['AccessKeyId'],
// Let the server return 200 Otherwise, the default returns 204
'success_action_status': '200',
'signature': OssUtil.instance.getSignature(data['AccessKeySecret']),
// Temporary user authorization must be carried back in the background security-token
'x-oss-security-token': data['SecurityToken'],
'file': new UploadFileInfo(
file, OssUtil.instance.getImageNameByPath(filePath))
// Must be placed at the end of the parameter
});
// Then put the form directly through the storage address (formdata) Upload ;
Dio dio=Dio();
dio.options.responseType=ResponseType.plain;
Response response=awaitdio.post(<ossEndPointCdn>,data:formData);
......tips: After successful upload, the picture address imageUrl = ossEndPointCdn + '/' + uploadName;
Give 1 tool class
import 'dart:convert';
import 'package:crypto/crypto.dart';
import 'dart:math';
class OssUtil {
Get
// Validate a text field
static String _policyText =
'{"expiration": "2069-05-22T03:15:00.000Z","conditions": [["content-length-range", 0, 1048576000]]}';//UTC Time +8= Beijing time
// Go on utf8 Code
// ignore: non_constant_identifier_names
static List<int> _policyText_utf8 = utf8.encode(_policyText);
// Go on base64 Code
static String policy= base64.encode(_policyText_utf8);
// Go on again utf8 Code
// ignore: non_constant_identifier_names
static List<int> _policy_utf8 = utf8.encode(policy);
// Factory model
factory OssUtil() => _getInstance();
static OssUtil get instance => _getInstance();
static OssUtil _instance;
OssUtil._internal();
static OssUtil _getInstance() {
if (_instance == null) {
_instance = new OssUtil._internal();
}
return _instance;
}
/*
* Get signature Signature parameter
*/
String getSignature(String _accessKeySecret){
// Go on utf8 Code
// ignore: non_constant_identifier_names
List<int> AccessKeySecretUtf8 = utf8.encode(_accessKeySecret);
// Pass hmac, Use sha1 Encrypt
List<int> signaturePre = new Hmac(sha1, AccessKeySecretUtf8).convert(_policy_utf8).bytes;
// Finally 1 Step of carrying out the above obtained base64 Code
String signature = base64.encode(signaturePre);
return signature;
}
// ignore: slash_for_doc_comments
/**
* Generate the name of the uploaded picture , Format obtained :photo/20171027175940_oCiobK
* You can define the upload path uploadPath(Oss The name of the save folder in the )
* @param uploadPath Upload path Such as: /photo
* @return photo/20171027175940_oCiobK
*/
String getImageUploadName(String uploadPath,String filePath) {
String imageMame = "";
var timestamp = new DateTime.now().millisecondsSinceEpoch;
imageMame =timestamp.toString()+"_"+getRandom(6);
if(uploadPath!=null&&uploadPath.isNotEmpty){
imageMame=uploadPath+"/"+imageMame;
}
String imageType=filePath?.substring(filePath?.lastIndexOf("."),filePath?.length);
return imageMame+imageType;
}
String getImageName(String filePath) {
String imageMame = "";
var timestamp = new DateTime.now().millisecondsSinceEpoch;
imageMame =timestamp.toString()+"_"+getRandom(6);
String imageType=filePath?.substring(filePath?.lastIndexOf("."),filePath?.length);
return imageMame+imageType;
}
/*
* Generate a random string of fixed length
* */
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;
}
/*
* Get the picture name according to the local path of the picture
* */
String getImageNameByPath(String filePath) {
// ignore: null_aware_before_operator
return filePath?.substring(filePath?.lastIndexOf("/")+1,filePath?.length);
}
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