Use a presigned URL to upload a file -Object Storage Service(OSS)-阿里云帮助中心

By default, the access control list (ACL) of an object in an Object Storage Service (OSS) bucket is private, and only the object owner has the permissions to access the object. You can use OSS SDK for Go to generate a presigned URL, which you can then share with a user to allow them to upload an object. When you generate the presigned URL, you can specify its validity period to limit the time during which the user can upload the object. During the validity period of the presigned URL, the user can use the URL to upload an object to the bucket multiple times. After the validity period of the presigned URL ends, the user can no longer use the presigned URL to upload an object. To prolong access for the user, regenerate a presigned URL.

Usage notes

In this topic, the public endpoint of the China (Hangzhou) region is used. To access OSS from other Alibaba Cloud services in the same region, use an internal endpoint. For details about supported regions and endpoints, see Regions and endpoints.
In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials (Go SDK V1).
This topic demonstrates creating an OSSClient instance with an OSS endpoint. For alternative configurations, such as using a custom domain or authenticating with credentials from Security Token Service (STS), see Client configuration.
Permissions are not required to generate a presigned URL. However, a third party can successfully upload a file using the presigned URL only if you have the oss:PutObject permission. For more information, see Grant a custom access policy to a RAM user.
In this topic, the signature algorithm V4 is used to generate presigned URLs with a validity period of up to 7 days. For more information, see (Recommended) V4 signatures in presigned URLs.

Process

The following figure shows how to use a presigned URL that allows HTTP PUT requests to upload a file to OSS.

Use a presigned URL for a simple upload

The object owner generates a presigned URL that allows HTTP PUT requests.

package main

import (
	"log"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Printf("Error: %v", err)
	}

	// Create an OSSClient instance. 
	// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.  
	// Specify the region of the bucket. For example, if your bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.  
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("cn-hangzhou"))
	// Specify the signature algorithm version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("https://oss-cn-hangzhou.aliyuncs.com", "", "", clientOptions...)
	if err != nil {
		log.Printf("Error: %v", err)
	}

	// Specify the name of the bucket. Example: examplebucket. 
	bucketName := "examplebucket"
	// Specify the full path of the object. Example: exampleobject.txt. Do not include the bucket name in the full path. 
	objectName := "exampleobject.txt"
	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Printf("Error: %v", err)
	}

	// Generate a presigned URL and set the validity period of the presigned URL to 600 seconds. 
	signedURL, err := bucket.SignURL(objectName, oss.HTTPPut, 600)
	if err != nil {
		log.Printf("Error: %v", err)
	}
	log.Printf("Sign Url:%s\n", signedURL)
}

A user uses the presigned URL to upload a local file.

curl

curl -X PUT -T /path/to/local/file "https://exampleobject.oss-cn-hangzhou.aliyuncs.com/exampleobject.txt?x-oss-date=20241112T083238Z&x-oss-expires=3599&x-oss-signature-version=OSS4-HMAC-SHA256&x-oss-credential=LTAI****************%2F20241112%2Fcn-hangzhou%2Foss%2Faliyun_v4_request&x-oss-signature=ed5a******************************************************"

Java

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.FileEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import java.io.*;
import java.net.URL;
import java.util.*;

public class SignUrlUpload {
    public static void main(String[] args) throws Throwable {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;

        // Replace <signedUrl> with the authorized URL.
        URL signedUrl = new URL("<signedUrl>");

        // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
        String pathName = "C:\\Users\\demo.txt";

        try {
            HttpPut put = new HttpPut(signedUrl.toString());
            System.out.println(put);
            HttpEntity entity = new FileEntity(new File(pathName));
            put.setEntity(entity);
            httpClient = HttpClients.createDefault();
            response = httpClient.execute(put);

            System.out.println("Status code returned for the upload:"+response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() == 200){
                System.out.println("Upload successful using network library.");
            }
            System.out.println(response.toString());
        } catch (Exception e){
            e.printStackTrace();
        } finally {
             if (response != null) {
                 response.close();
             }
             if (httpClient != null) {
                 httpClient.close();
             }
         }
    }
}

Go

package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
)

func uploadFile(signedUrl, filePath string) error {
	// Open the file.
	file, err := os.Open(filePath)
	if err != nil {
		return fmt.Errorf("Unable to open file: %w", err)
	}
	defer file.Close()

	// Create a new HTTP client.
	client := &http.Client{}

	// Create a PUT request.
	req, err := http.NewRequest("PUT", signedUrl, file)
	if err != nil {
		return fmt.Errorf("Failed to create request: %w", err)
	}

	// Send the request.
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("Failed to send request: %w", err)
	}
	defer resp.Body.Close()

	// Read the response.
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("Failed to read response: %w", err)
	}

	fmt.Printf("Status code returned for the upload: %d\n", resp.StatusCode)
	if resp.StatusCode == 200 {
		fmt.Println("Upload successful using network library.")
	}
	fmt.Println(string(body))

	return nil
}

func main() {
	// Replace <signedUrl> with the authorized URL.
	signedUrl := "<signedUrl>"

	// Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
	filePath := "C:\\Users\\demo.txt"

	err := uploadFile(signedUrl, filePath)
	if err != nil {
		fmt.Println("An error occurred:", err)
	}
}

python

import requests

def upload_file(signed_url, file_path):
    try:
        # Open the file.
        with open(file_path, 'rb') as file:
            # Send a PUT request to upload the file.
            response = requests.put(signed_url, data=file)
     
        print(f"Status code returned for the upload: {response.status_code}")
        if response.status_code == 200:
            print("Upload successful using network library.")
        print(response.text)
 
    except Exception as e:
        print(f"An error occurred: {e}")

if __name__ == "__main__":
    # Replace <signedUrl> with the authorized URL.
    signed_url = "<signedUrl>"
    
    # Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
    file_path = "C:\\Users\\demo.txt"

    upload_file(signed_url, file_path)

Node.js

const fs = require('fs');
const axios = require('axios');

async function uploadFile(signedUrl, filePath) {
    try {
        // Create a read stream.
        const fileStream = fs.createReadStream(filePath);
        
        // Send a PUT request to upload the file.
        const response = await axios.put(signedUrl, fileStream, {
            headers: {
                'Content-Type': 'application/octet-stream' // Adjust the Content-Type as needed.
            }
        });

        console.log(`Status code returned for the upload: ${response.status}`);
        if (response.status === 200) {
            console.log('Upload successful using network library.');
        }
        console.log(response.data);
    } catch (error) {
        console.error(`An error occurred: ${error.message}`);
    }
}

// Main function.
(async () => {
    // Replace <signedUrl> with the authorized URL.
    const signedUrl = '<signedUrl>';
    
    // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
    const filePath = 'C:\\Users\\demo.txt';

    await uploadFile(signedUrl, filePath);
})();

browser.js

Important

If you encounter a 403 signature mismatch error when you use Browser.js to upload a file, it is usually because the browser automatically adds the Content-Type request header, and this header was not included when the presigned URL was generated. This mismatch causes a signature verification failure. To resolve this issue, you must specify the Content-Type request header when you generate the presigned URL.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>File Upload Example</title>
</head>
<body>
    <h1>File Upload Example</h1>

    <!-- Select a file -->
    <input type="file" id="fileInput" />
    <button id="uploadButton">Upload File</button>

    <script>
        // Replace this with the presigned URL generated in Step 1.
        const signedUrl = "<signedUrl>"; 


        document.getElementById('uploadButton').addEventListener('click', async () => {
            const fileInput = document.getElementById('fileInput');
            const file = fileInput.files[0];

            if (!file) {
                alert('Please select a file to upload.');
                return;
            }

            try {
                await upload(file, signedUrl);
                alert('File uploaded successfully!');
            } catch (error) {
                console.error('Error during upload:', error);
                alert('Upload failed: ' + error.message);
            }
        });

        /**
         * Upload the file to OSS.
         * @param {File} file - The file to upload.
         * @param {string} presignedUrl - The presigned URL.
         */
        const upload = async (file, presignedUrl) => {
            const response = await fetch(presignedUrl, {
                method: 'PUT',
                body: file,  // Upload the entire file directly.
            });

            if (!response.ok) {
                throw new Error(`Upload failed, status: ${response.status}`);
            }

            console.log('File uploaded successfully');
        };
    </script>
</body>
</html>

C#

using System.Net.Http.Headers;

// Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
var filePath = "C:\\Users\\demo.txt";
// Replace <signedUrl> with the authorized URL.
var presignedUrl = "<signedUrl>";

// Create an HTTP client and open the local file stream.
using var httpClient = new HttpClient(); 
using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
using var content = new StreamContent(fileStream);
            
// Create a PUT request.
var request = new HttpRequestMessage(HttpMethod.Put, presignedUrl);
request.Content = content;

// Send the request.
var response = await httpClient.SendAsync(request);

// Process the response.
if (response.IsSuccessStatusCode)
{
    Console.WriteLine($"Upload successful! Status code: {response.StatusCode}");
    Console.WriteLine("Response headers:");
    foreach (var header in response.Headers)
    {
        Console.WriteLine($"{header.Key}: {string.Join(", ", header.Value)}");
    }
}
else
{
    string responseContent = await response.Content.ReadAsStringAsync();
    Console.WriteLine($"Upload failed! Status code: {response.StatusCode}");
    Console.WriteLine("Response content: " + responseContent);
}

C++

#include <iostream>
#include <fstream>
#include <curl/curl.h>

void uploadFile(const std::string& signedUrl, const std::string& filePath) {
    CURL *curl;
    CURLcode res;

    curl_global_init(CURL_GLOBAL_DEFAULT);
    curl = curl_easy_init();

    if (curl) {
        // Set the URL.
        curl_easy_setopt(curl, CURLOPT_URL, signedUrl.c_str());

        // Set the request method to PUT.
        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

        // Open the file.
        FILE *file = fopen(filePath.c_str(), "rb");
        if (!file) {
            std::cerr << "Unable to open file: " << filePath << std::endl;
            return;
        }

        // Get the file size.
        fseek(file, 0, SEEK_END);
        long fileSize = ftell(file);
        fseek(file, 0, SEEK_SET);

        // Set the file size.
        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fileSize);

        // Set the input file handle.
        curl_easy_setopt(curl, CURLOPT_READDATA, file);

        // Execute the request.
        res = curl_easy_perform(curl);

        if (res != CURLE_OK) {
            std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
        } else {
            long httpCode = 0;
            curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpCode);
            std::cout << "Status code returned for the upload: " << httpCode << std::endl;

            if (httpCode == 200) {
                std::cout << "Upload successful using network library." << std::endl;
            }
        }

        // Close the file.
        fclose(file);

        // Clean up.
        curl_easy_cleanup(curl);
    }

    curl_global_cleanup();
}

int main() {
    // Replace <signedUrl> with the authorized URL.
    std::string signedUrl = "<signedUrl>";

    // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
    std::string filePath = "C:\\Users\\demo.txt";

    uploadFile(signedUrl, filePath);

    return 0;
}

Android

package com.example.signurlupload;

import android.os.AsyncTask;
import android.util.Log;

import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class SignUrlUploadActivity {

    private static final String TAG = "SignUrlUploadActivity";

    public void uploadFile(String signedUrl, String filePath) {
        new UploadTask().execute(signedUrl, filePath);
    }

    private class UploadTask extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... params) {
            String signedUrl = params[0];
            String filePath = params[1];

            HttpURLConnection connection = null;
            DataOutputStream dos = null;
            FileInputStream fis = null;

            try {
                URL url = new URL(signedUrl);
                connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("PUT");
                connection.setDoOutput(true);
                connection.setRequestProperty("Content-Type", "application/octet-stream");

                fis = new FileInputStream(filePath);
                dos = new DataOutputStream(connection.getOutputStream());

                byte[] buffer = new byte[1024];
                int length;

                while ((length = fis.read(buffer)) != -1) {
                    dos.write(buffer, 0, length);
                }

                dos.flush();
                dos.close();
                fis.close();

                int responseCode = connection.getResponseCode();
                Log.d(TAG, "Status code returned for the upload: " + responseCode);

                if (responseCode == 200) {
                    Log.d(TAG, "Upload successful using network library.");
                }

                return "Upload complete. Status code: " + responseCode;

            } catch (IOException e) {
                e.printStackTrace();
                return "Upload failed: " + e.getMessage();
            } finally {
                if (connection != null) {
                    connection.disconnect();
                }
            }
        }

        @Override
        protected void onPostExecute(String result) {
            Log.d(TAG, result);
        }
    }

    public static void main(String[] args) {
        SignUrlUploadActivity activity = new SignUrlUploadActivity();
        // Replace <signedUrl> with the authorized URL.
        String signedUrl = "<signedUrl>";
        // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
        String filePath = "C:\\Users\\demo.txt";
        activity.uploadFile(signedUrl, filePath);
    }
}

Common scenarios

Use a presigned URL that contains specific request headers and user metadata to upload a file

The object owner generates a presigned URL that contains specific request headers and user metadata and allows HTTP PUT requests.

package main

import (
	"log"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Printf("Error: %v", err)
	}

	// Create an OSSClient instance. 
	// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.  
	// Specify the region of the bucket. For example, if your bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.  
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("cn-hangzhou"))
	// Specify the signature algorithm version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("https://oss-cn-hangzhou.aliyuncs.com", "", "", clientOptions...)
	if err != nil {
		log.Printf("Error: %v", err)
	}

	// Specify the name of the bucket. Example: examplebucket. 
	bucketName := "examplebucket"
	// Specify the full path of the object. Example: exampleobject.txt. Do not include the bucket name in the full path. 
	objectName := "exampleobject.txt"
	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Printf("Error: %v", err)
	}
	// Note that when you use a presigned URL that contains custom parameters on the frontend, you must specify the same content type as the one that is specified here to generate the presigned URL. 
	options := []oss.Option{
		oss.Meta("key1", "value1"),
		oss.Meta("key2", "value2"),
		oss.ContentType("text/plain; charset=utf8"),
	}

	// Generate a presigned URL and set the validity period of the presigned URL to 600 seconds. 
	signedURL, err := bucket.SignURL(objectName, oss.HTTPPut, 600, options...)
	if err != nil {
		log.Printf("Error: %v", err)
	}
	log.Printf("Sign Url:%s\n", signedURL)
}

A user uses the presigned URL to upload a local file.

curl

curl -X PUT \
     -H "Content-Type: text/plain;charset=utf8" \
     -H "x-oss-storage-class: Standard" \
     -H "x-oss-meta-key1: value1" \
     -H "x-oss-meta-key2: value2" \
     -T "C:\\Users\\demo.txt" \
     "https://exampleobject.oss-cn-hangzhou.aliyuncs.com/exampleobject.txt?x-oss-date=20241112T083238Z&x-oss-expires=3599&x-oss-signature-version=OSS4-HMAC-SHA256&x-oss-credential=LTAI****************%2F20241112%2Fcn-hangzhou%2Foss%2Faliyun_v4_request&x-oss-signature=ed5a******************************************************"

Java

package com.aliyun.sample;

import com.aliyun.oss.internal.OSSHeaders;
import com.aliyun.oss.model.StorageClass;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.FileEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import java.io.*;
import java.net.URL;
import java.util.*;

public class SignUrlUpload {
    public static void main(String[] args) throws Throwable {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;

        // Replace <signedUrl> with the authorized URL.
        URL signedUrl = new URL("<signedUrl>");

        // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
        String pathName = "C:\\Users\\demo.txt";

        // Set the request headers. The request header information must be the same as the information used when the URL was generated.
        Map<String, String> headers = new HashMap<String, String>();
        //Specify the storage class of the object.
        headers.put(OSSHeaders.STORAGE_CLASS, StorageClass.Standard.toString());
        //Specify the ContentType.
        headers.put(OSSHeaders.CONTENT_TYPE, "text/plain;charset=utf8");

        // Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
        Map<String, String> userMetadata = new HashMap<String, String>();
        userMetadata.put("key1","value1");
        userMetadata.put("key2","value2");

        try {
            HttpPut put = new HttpPut(signedUrl.toString());
            System.out.println(put);
            HttpEntity entity = new FileEntity(new File(pathName));
            put.setEntity(entity);
            // If you set header parameters, such as user metadata and storage class, when you generate the presigned URL, you must also send these parameters to the server when you use the presigned URL to upload the file. A signature error is reported if the parameters sent to the server are inconsistent with the signed parameters.
            for(Map.Entry<String, String> header: headers.entrySet()){
                put.addHeader(header.getKey(), header.getValue());
            }
            for(Map.Entry<String, String> meta: userMetadata.entrySet()){
                // If you use userMeta, the SDK internally adds the 'x-oss-meta-' prefix. When you use other methods to generate a presigned URL for an upload, you must also add the 'x-oss-meta-' prefix to the userMeta.
                put.addHeader("x-oss-meta-"+meta.getKey(), meta.getValue());
            }

            httpClient = HttpClients.createDefault();

            response = httpClient.execute(put);

            System.out.println("Status code returned for the upload:"+response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() == 200){
                System.out.println("Upload successful using network library.");
            }
            System.out.println(response.toString());
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            if (response != null) {
                response.close();
            }
            if (httpClient != null) {
                httpClient.close();
            }
        }
    }
}

Go

package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
)

func uploadFile(signedUrl string, filePath string, headers map[string]string, metadata map[string]string) error {
	// Open the file.
	file, err := os.Open(filePath)
	if err != nil {
		return err
	}
	defer file.Close()

	// Read the file content.
	fileBytes, err := ioutil.ReadAll(file)
	if err != nil {
		return err
	}

	// Create a request.
	req, err := http.NewRequest("PUT", signedUrl, bytes.NewBuffer(fileBytes))
	if err != nil {
		return err
	}

	// Set the request headers.
	for key, value := range headers {
		req.Header.Set(key, value)
	}

	// Set the custom user metadata.
	for key, value := range metadata {
		req.Header.Set(fmt.Sprintf("x-oss-meta-%s", key), value)
	}

	// Send the request.
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Process the response.
	fmt.Printf("Status code returned for the upload: %d\n", resp.StatusCode)
	if resp.StatusCode == 200 {
		fmt.Println("Upload successful using network library.")
	} else {
		fmt.Println("Upload failed.")
	}
	body, _ := ioutil.ReadAll(resp.Body)
	fmt.Println(string(body))

	return nil
}

func main() {
	// Replace <signedUrl> with the authorized URL.
	signedUrl := "<signedUrl>"

	// Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
	filePath := "C:\\Users\\demo.txt"

	// Set the request headers. The request header information must be the same as the information used when the URL was generated.
	headers := map[string]string{
		"Content-Type": "text/plain;charset=utf8",
		"x-oss-storage-class": "Standard",
	}

	// Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
	metadata := map[string]string{
		"key1": "value1",
		"key2": "value2",
	}

	err := uploadFile(signedUrl, filePath, headers, metadata)
	if err != nil {
		fmt.Printf("An error occurred: %v\n", err)
	}
}

Python

import requests
from requests.auth import HTTPBasicAuth
import os

def upload_file(signed_url, file_path, headers=None, metadata=None):
    """
    Use a presigned URL to upload a file to OSS.

    :param signed_url: The presigned URL.
    :param file_path: The full path of the file to upload.
    :param headers: Optional. Custom HTTP headers.
    :param metadata: Optional. Custom metadata.
    :return: None
    """
    if not headers:
        headers = {}
    if not metadata:
        metadata = {}

    # Update headers and add the metadata prefix.
    for key, value in metadata.items():
        headers[f'x-oss-meta-{key}'] = value

    try:
        with open(file_path, 'rb') as file:
            response = requests.put(signed_url, data=file, headers=headers)
            print(f"Status code returned for the upload: {response.status_code}")
            if response.status_code == 200:
                print("Upload successful using network library.")
            else:
                print("Upload failed.")
            print(response.text)
    except Exception as e:
        print(f"An error occurred: {e}")

if __name__ == "__main__":
    # Replace <signedUrl> with the authorized URL.
    signed_url = "<signedUrl>"
   
    # Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the directory where the script is located by default.
    file_path = "C:\\Users\\demo.txt"

    # Set the request headers. The request header information must be the same as the information used when the URL was generated.
    headers = {
         "Content-Type": "text/plain;charset=utf8",
         "x-oss-storage-class": "Standard"
    }

    # Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
    metadata = {
         "key1": "value1",
         "key2": "value2"
    }

    upload_file(signed_url, file_path, headers, metadata)

Node.js

const fs = require('fs');
const axios = require('axios');

async function uploadFile(signedUrl, filePath, headers = {}, metadata = {}) {
    try {
        // Update headers and add the metadata prefix.
        for (const [key, value] of Object.entries(metadata)) {
            headers[`x-oss-meta-${key}`] = value;
        }

        // Read the file stream.
        const fileStream = fs.createReadStream(filePath);

        // Send a PUT request.
        const response = await axios.put(signedUrl, fileStream, {
            headers: headers
        });

        console.log(`Status code returned for the upload: ${response.status}`);
        if (response.status === 200) {
            console.log("Upload successful using network library.");
        } else {
            console.log("Upload failed.");
        }
        console.log(response.data);
    } catch (error) {
        console.error(`An error occurred: ${error.message}`);
    }
}

// Main function.
(async () => {
    // Replace <signedUrl> with the authorized URL.
    const signedUrl = "<signedUrl>";

    // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the directory where the script is located by default.
    const filePath = "C:\\Users\\demo.txt";

    // Set the request headers. The request header information must be the same as the information used when the URL was generated.
    const headers = {
         "Content-Type": "text/plain;charset=utf8",
         "x-oss-storage-class": "Standard"
    };

    // Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
    const metadata = {
         "key1": "value1",
         "key2": "value2"
    };

    await uploadFile(signedUrl, filePath, headers, metadata);
})();

Browser.js

Important

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>File Upload Example</title>
</head>
<body>
    <h1>File Upload Example (Java SDK)</h1>

    <input type="file" id="fileInput" />
    <button id="uploadButton">Upload File</button>

    <script>
        // Replace this with the actual presigned URL.
        const signedUrl = "<signedUrl>"; 

        document.getElementById('uploadButton').addEventListener('click', async () => {
            const fileInput = document.getElementById('fileInput');
            const file = fileInput.files[0];

            if (file) {
                try {
                    await upload(file, signedUrl);
                } catch (error) {
                    console.error('Error during upload:', error);
                    alert('Upload failed: ' + error.message);
                }
            } else {
                alert('Please select a file to upload.');
            }
        });

        const upload = async (file, presignedUrl) => {
            const headers = {
                "Content-Type": "text/plain;charset=utf8",
                'x-oss-storage-class': 'Standard',
                'x-oss-meta-key1': 'value1',
                'x-oss-meta-key2': 'value2'
            };

            const response = await fetch(presignedUrl, {
                method: 'PUT',
                headers: headers,
                body: file
            });

            if (!response.ok) {
                throw new Error(`Upload failed, status: ${response.status}`);
            }

            alert('File uploaded successfully');
            console.log('File uploaded successfully');
        };
    </script>
</body>
</html>

C#

using System.Net.Http.Headers;

// Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
var filePath = "C:\\Users\\demo.txt";
// Replace <signedUrl> with the authorized URL.
var presignedUrl = "<signedUrl>";

// Create an HTTP client and open the local file stream.
using var httpClient = new HttpClient(); 
using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
using var content = new StreamContent(fileStream);
            
// Create a PUT request.
var request = new HttpRequestMessage(HttpMethod.Put, presignedUrl);
request.Content = content;

// If you set header parameters, such as user metadata and storage class, when you generate the presigned URL, you must also send these parameters to the server when you use the presigned URL to upload the file. A signature error is reported if the parameters sent to the server are inconsistent with the signed parameters.
// Set the request headers. The request header information must be the same as the information used when the URL was generated.
request.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain") { CharSet = "utf8" };  // Specify the ContentType.       
// Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
request.Content.Headers.Add("x-oss-meta-key1", "value1");
request.Content.Headers.Add("x-oss-meta-key2", "value2");
// Specify the storage class of the object.
request.Content.Headers.Add("x-oss-storage-class", "Standard");

// Print the request headers.
Console.WriteLine("Request headers:");
foreach (var header in request.Content.Headers)
{
    Console.WriteLine($"{header.Key}: {string.Join(", ", header.Value)}");
}

// Send the request.
var response = await httpClient.SendAsync(request);

// Process the response.
if (response.IsSuccessStatusCode)
{
    Console.WriteLine($"Upload successful! Status code: {response.StatusCode}");
    Console.WriteLine("Response headers:");
    foreach (var header in response.Headers)
    {
        Console.WriteLine($"{header.Key}: {string.Join(", ", header.Value)}");
    }
}
else
{
    string responseContent = await response.Content.ReadAsStringAsync();
    Console.WriteLine($"Upload failed! Status code: {response.StatusCode}");
    Console.WriteLine("Response content: " + responseContent);
}

C++

#include <iostream>
#include <fstream>
#include <curl/curl.h>
#include <map>
#include <string>

// Callback function to handle the HTTP response.
size_t WriteCallback(void* contents, size_t size, size_t nmemb, std::string* output) {
    size_t totalSize = size * nmemb;
    output->append((char*)contents, totalSize);
    return totalSize;
}

void uploadFile(const std::string& signedUrl, const std::string& filePath, const std::map<std::string, std::string>& headers, const std::map<std::string, std::string>& metadata) {
    CURL* curl;
    CURLcode res;
    std::string readBuffer;

    curl_global_init(CURL_GLOBAL_DEFAULT);
    curl = curl_easy_init();

    if (curl) {
        // Set the URL.
        curl_easy_setopt(curl, CURLOPT_URL, signedUrl.c_str());

        // Set the request method to PUT.
        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

        // Open the file.
        FILE* file = fopen(filePath.c_str(), "rb");
        if (!file) {
            std::cerr << "Unable to open file: " << filePath << std::endl;
            return;
        }

        // Set the file size.
        fseek(file, 0, SEEK_END);
        long fileSize = ftell(file);
        rewind(file);

        // Set the file read callback.
        curl_easy_setopt(curl, CURLOPT_READDATA, file);
        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fileSize);

        // Set the request headers.
        struct curl_slist* chunk = nullptr;
        for (const auto& header : headers) {
            std::string headerStr = header.first + ": " + header.second;
            chunk = curl_slist_append(chunk, headerStr.c_str());
        }
        for (const auto& meta : metadata) {
            std::string metaStr = "x-oss-meta-" + meta.first + ": " + meta.second;
            chunk = curl_slist_append(chunk, metaStr.c_str());
        }
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);

        // Set the response handling callback.
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);

        // Execute the request.
        res = curl_easy_perform(curl);

        // Check the response.
        if (res != CURLE_OK) {
            std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
        } else {
            long responseCode;
            curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &responseCode);
            std::cout << "Status code returned for the upload: " << responseCode << std::endl;
            if (responseCode == 200) {
                std::cout << "Upload successful using network library." << std::endl;
            } else {
                std::cout << "Upload failed." << std::endl;
            }
            std::cout << readBuffer << std::endl;
        }

        // Clean up.
        fclose(file);
        curl_slist_free_all(chunk);
        curl_easy_cleanup(curl);
    }

    curl_global_cleanup();
}

int main() {
    // Replace <signedUrl> with the authorized URL.
    std::string signedUrl = "<signedUrl>";

    // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
    std::string filePath = "C:\\Users\\demo.txt";

    // Set the request headers. The request header information must be the same as the information used when the URL was generated.
    std::map<std::string, std::string> headers = {
         {"Content-Type", "text/plain;charset=utf8"},
         {"x-oss-storage-class", "Standard"}
    };

    // Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
    std::map<std::string, std::string> metadata = {
         {"key1", "value1"},
         {"key2", "value2"}
    };

    uploadFile(signedUrl, filePath, headers, metadata);

    return 0;
}

Android

import android.os.AsyncTask;
import android.util.Log;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

public class SignUrlUploadActivity extends AppCompatActivity {

    private static final String TAG = "SignUrlUploadActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Replace <signedUrl> with the authorized URL.
        String signedUrl = "<signedUrl>";

        // Specify the full path of the local file. If you do not specify a local path, the file is uploaded from the project path of the sample program by default.
        String pathName = "/storage/emulated/0/demo.txt";

        // Set the request headers. The request header information must be the same as the information used when the URL was generated.
        Map<String, String> headers = new HashMap<>();
        headers.put("Content-Type", "text/plain;charset=utf8");
        headers.put("x-oss-storage-class", "Standard");

        // Set the custom user metadata. The custom user metadata must be the same as the information used when the URL was generated.
        Map<String, String> userMetadata = new HashMap<>();
        userMetadata.put("key1", "value1");
        userMetadata.put("key2", "value2");

        new UploadTask().execute(signedUrl, pathName, headers, userMetadata);
    }

    private class UploadTask extends AsyncTask<Object, Void, Integer> {
        @Override
        protected Integer doInBackground(Object... params) {
            String signedUrl = (String) params[0];
            String pathName = (String) params[1];
            Map<String, String> headers = (Map<String, String>) params[2];
            Map<String, String> userMetadata = (Map<String, String>) params[3];

            try {
                URL url = new URL(signedUrl);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("PUT");
                connection.setDoOutput(true);
                connection.setUseCaches(false);

                // Set the request headers.
                for (Entry<String, String> header : headers.entrySet()) {
                    connection.setRequestProperty(header.getKey(), header.getValue());
                }

                // Set the custom user metadata.
                for (Entry<String, String> meta : userMetadata.entrySet()) {
                    connection.setRequestProperty("x-oss-meta-" + meta.getKey(), meta.getValue());
                }

                // Read the file.
                File file = new File(pathName);
                FileInputStream fileInputStream = new FileInputStream(file);
                DataOutputStream dos = new DataOutputStream(connection.getOutputStream());

                byte[] buffer = new byte[1024];
                int count;
                while ((count = fileInputStream.read(buffer)) != -1) {
                    dos.write(buffer, 0, count);
                }

                fileInputStream.close();
                dos.flush();
                dos.close();

                // Get the response.
                int responseCode = connection.getResponseCode();
                Log.d(TAG, "Status code returned for the upload: " + responseCode);
                if (responseCode == 200) {
                    Log.d(TAG, "Upload successful using network library.");
                } else {
                    Log.d(TAG, "Upload failed.");
                }

                InputStream is = connection.getInputStream();
                byte[] responseBuffer = new byte[1024];
                StringBuilder responseStringBuilder = new StringBuilder();
                while ((count = is.read(responseBuffer)) != -1) {
                    responseStringBuilder.append(new String(responseBuffer, 0, count));
                }
                Log.d(TAG, responseStringBuilder.toString());

                return responseCode;
            } catch (IOException e) {
                e.printStackTrace();
                return -1;
            }
        }

        @Override
        protected void onPostExecute(Integer result) {
            super.onPostExecute(result);
            if (result == 200) {
                Toast.makeText(SignUrlUploadActivity.this, "Upload successful.", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(SignUrlUploadActivity.this, "Upload failed.", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

Use presigned URLs for a multipart upload

To upload an object in parts by using presigned URLs, you must configure the part size and generate a presigned URL for each part. The following sample code uses presigned URLs for a multipart upload:

package main

import (
	"crypto/md5"
	"encoding/base64"
	"fmt"
	"log"
	"os"
	"strconv"
	"strings"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Printf("Error:%v", err)
	}
	// Create an OSSClient instance. 
	// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.  
	client, err := oss.New("yourEndpoint", "", "", oss.SetCredentialsProvider(&provider))
	if err != nil {
		log.Printf("Error:%v", err)
	}
	bucketName := "bucket_name"

	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Printf("Error:%v", err)
	}
	// Specify the full path of the object. Do not include the bucket name in the full path. 
	objectName := "example.txt"
	// Specify the full path of the local file that you want to upload. If the path of the local file is not specified, the local file is uploaded from the path of the project to which the sample program belongs. 
	localFile := "D:\\download\\demo.txt"

	// Split the local file into three parts. 
	chunks, err := oss.SplitFileByPartNum(localFile, 3)
	fd, err := os.Open(localFile)
	defer fd.Close()
	// Step 1: Initiate a multipart upload task and set the storage class of the object to Standard. 
	imur, err := bucket.InitiateMultipartUpload(objectName)
	// Step 2: Upload the parts. 
	var options []oss.Option

	for _, chunk := range chunks {
		// Configure MD5 verification. 
		buf := make([]byte, chunk.Size)
		fd.ReadAt(buf, chunk.Size)
		sum := md5.Sum(buf)
		b64 := base64.StdEncoding.EncodeToString(sum[:])
		options = []oss.Option{
			oss.ContentMD5(b64),
		}

		options = append(options, oss.AddParam("partNumber", strconv.Itoa(chunk.Number)))
		options = append(options, oss.AddParam("uploadId", imur.UploadID))
		// Generate a presigned URL. 
		signedURL, err := bucket.SignURL(objectName, oss.HTTPPut, 60, options...)
		if err != nil {
			log.Printf("Error:%v", err)
		}
		fmt.Printf("Presigned URL: %s\n", signedURL)
		err = bucket.PutObjectWithURL(signedURL, strings.NewReader(string(buf)), options...)
		if err != nil {
			log.Printf("Error:%v", err)
		}
	}

	lsRes, err := bucket.ListUploadedParts(imur)
	if err != nil {
		log.Printf("Error:%v", err)
	}

	// Traverse the parts and populate partETags. 
	var parts []oss.UploadPart
	for _, p := range lsRes.UploadedParts {
		parts = append(parts, oss.UploadPart{XMLName: p.XMLName, PartNumber: p.PartNumber, ETag: p.ETag})
	}

	// Step 3: Complete the multipart upload task. 
	_, err = bucket.CompleteMultipartUpload(imur, parts)
	if err != nil {
		log.Printf("Error:%v", err)
	}
	fmt.Println("Uploaded")
}

FAQ

When I use a presigned URL to upload a local file, will the file upload fail if the presigned URL expires during the upload?

No, the file upload will not fail, even if the presigned URL expires during the upload process.

A presigned URL can be used within its validity period, which is determined by the shorter duration of the token validity and the signature validity.

If I do not specify request headers and user metadata when I generate a URL, do I need to specify request headers and user metadata when I use the URL to upload a local file?

No, you do not need to specify request headers and user metadata.

The request headers and user metadata are optional parameters. If you do not specify request headers and user metadata, delete the relevant code in the preceding examples.

References

For the complete sample code that uploads files by using presigned URLs, visit GitHub.
For more information about the API operation that presigns a URL, see SignURL.