Use a presigned URL to upload an object - Object Storage Service

By default, the access control list (ACL) of an object in an Object Storage Service (OSS) bucket is private. Only the object owner has the permissions to access the object. You can use OSS SDK for Python to generate a presigned URL and share the presigned URL with a user to allow the user to upload an object. When you generate a presigned URL, you can specify the validity period of the presigned URL to limit the period of time during which the user can upload an 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 cannot use the presigned URL to upload an object. In this case, you must generate a new presigned URL.

Usage notes

In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.
In this topic, access credentials are obtained from environment variables. For more information about how to configure the access credentials, see Configure access credentials.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.
You do not need specific permissions to generate a presigned URL. However, to allow others to use the presigned URL for uploading an object, you must have the oss:PutObject permission. For more information, see Example 5: Authorize a RAM user to access multiple directories in a bucket.
In this topic, the V4 signature algorithm is used to generate presigned URLs that have a validity period of up to 7 days. For more information, see (Recommended) Include a V4 signature in a URL.

Process

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

Sample code

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

# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider

# 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. 
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())

# 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. 
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"

# Specify the region in which the bucket is located. Example: cn-hangzhou. This parameter is required if you use the V4 signature algorithm.
region = "cn-hangzhou"

# Specify the name of the bucket. 
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)

# Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
object_name = 'exampledir/exampleobject.txt'

# Generate a presigned URL that is used to upload a local file. Set the validity period of the presigned URL to 60 seconds. 
# By default, OSS identifies the forward slashes (/) in the full path of an object as escape characters when a presigned URL is generated. Therefore, you cannot directly use the presigned URL. 
# Set the slash_safe parameter to True. This way, OSS does not identify forward slashes (/) in the full path of the object as escape characters. In this case, you can directly use the presigned URL. 
url = bucket.sign_url('PUT', object_name, 60, slash_safe=True)
print('The presigned URL:', url)

A user uses the presigned URL that allows HTTP PUT requests to upload an object.

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 presigned URL. 
        URL signedUrl = new URL("<signedUrl>");

        // 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. 
        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 of the upload: "+response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() == 200){
                System.out.println("The object is uploaded by using the library.");
            }
            System.out.println(response.toString());
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            response.close();
            httpClient.close();
        }
    }
}

Go

package main

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

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

	// Create an 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 the request: %w", err)
	}

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

	fmt.Printf("Status code: %d\n", resp.StatusCode)
	if resp.StatusCode == 200 {
		fmt.Println("The object is uploaded by using the library.")
	}
	fmt.Println(string(body))

	return nil
}

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

	// 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. 
	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 local file that you want to upload.
        with open(file_path, 'rb') as file:
            # Send a PUT request to upload the local file.
            response = requests.put(signed_url, data=file)
     
        print(f"Status code: {response.status_code}")
        if response.status_code == 200:
            print("The object is uploaded by using the library.")
        print(response.text)
 
    except Exception as e:
        print(f"An error occurred: {e}")

if __name__ == "__main__":
    # Replace <signedUrl> with the generated signed URL. 
    signed_url = "<signedUrl>"
    
    # Specify the full path of the local file. 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. 
    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 local file.
        const response = await axios.put(signedUrl, fileStream, {
            headers: {
                'Content-Type': 'application/octet-stream' // Specify the Content-Type parameter.
            }
        });

        console.log(`Status code: ${response.status}`);
        if (response.status === 200) {
            console.log("The object is uploaded by using the library.");
        }
        console.log(response.data);
    } catch (error) {
        console.error(`An error occurred: ${error.message}`);
    }
}

// Specify the main function.
(async () => {
    // Replace <signedUrl> with the presigned URL. 
    const signedUrl = '<signedUrl>';
    
    // 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. 
    const filePath = 'C:\\Users\\demo.txt';

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

browser.js

Important

When you use Browser.js code to upload an object based on a presigned URL, you may encounter a 403 error that indicates a signature inconsistency. This error arises from a signature verification failure, which occurs because the browser automatically adds the Content-Type request header, an element that was not specified when the presigned URL was generated. To resolve the error, you must specify the Content-Type header when you generate a presigned URL that is expected to be used in Browser.js code to upload data to OSS.

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

    <script>
        // Replace <signedUrl> with the presigned URL that was 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 a file to OSS.
         * @param {File} file - The file to be uploaded.
         * @param {string} presignedUrl - The presigned URL.
         */
        const upload = async (file, presignedUrl) => {
            const response = await fetch(presignedUrl, {
                method: 'PUT',
                body: file,  // Upload the entire file.
            });

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

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

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

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

        // Specify the size of the local file.
        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fileSize);

        // Specify 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: " << httpCode << std::endl;

            if (httpCode == 200) {
                std::cout << "The object is uploaded by using the network library." << std::endl;
            }
        }

        // Close the local file.
        fclose(file);

        // Clear the cURL handle.
        curl_easy_cleanup(curl);
    }

    curl_global_cleanup();
}

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

    // 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. 
    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: " + responseCode);

                if (responseCode == 200) {
                    Log.d(TAG, "The object is uploaded by using the library.");
                }

                return "Object uploaded. 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 presigned URL. 
        String signedUrl = "<signedUrl>";
        // 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. 
        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 an object

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

# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider

# 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. 
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())

# 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. 
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"

# Specify the region in which the bucket is located. Example: cn-hangzhou. This parameter is required if you use the V4 signature algorithm.
region = "cn-hangzhou"

# Specify the name of the bucket. 
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)

# Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
object_name = 'exampledir/exampleobject.txt'

# Specify request headers. 
headers = dict()
# Specify the Content-Type header. 
headers['Content-Type'] = 'text/plain; charset=utf8'
# Specify the storage class of the object. 
headers["x-oss-storage-class"] = "Standard"

# Specify user metadata.
metadata = {'key1': 'value1', 'key2': 'value2'}
# Add the x-oss-meta- prefix to the metadata key.
for key, value in metadata.items():
    headers[f'x-oss-meta-{key}'] = value

# Generate a presigned URL that is used to upload a local file. Set the validity period of the presigned URL to 60 seconds. 
# By default, OSS identifies the forward slashes (/) in the full path of an object as escape characters when a presigned URL is generated. Therefore, you cannot directly use the presigned URL. 
# Set the slash_safe parameter to True. This way, OSS does not identify forward slashes (/) in the full path of the object as escape characters. In this case, you can directly use the presigned URL. 
url = bucket.sign_url('PUT', object_name, 60, slash_safe=True, headers=headers)
print('The presigned URL:', url)

A user uses the presigned URL that allows HTTP PUT requests to upload an object.

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

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 presigned URL. 
        URL signedUrl = new URL("<signedUrl>");

        // 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. 
        String pathName = "C:\\Users\\demo.txt";

        // Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned 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 content type. 
        headers.put(OSSHeaders.CONTENT_TYPE, "text/plain;charset=utf8");

        // Specify user metadata. Make sure that the user metadata here is the same as the user metadata specified when the presigned 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 configure headers such as the user metadata and storage class when the presigned URL was generated, these headers must be sent to the server when the presigned URL is used to upload a file. If the headers that are sent to the server for the signature calculation are different from the headers specified when the presigned URL was generated, a signature error is reported. 
            for(Map.Entry header: headers.entrySet()){
                put.addHeader(header.getKey().toString(),header.getValue().toString());
            }
            for(Map.Entry meta: userMetadata.entrySet()){
                // If user metadata is specified, the SDK adds the "x-oss-meta-" prefix to the user metadata key. If you use other methods to upload a file, make sure that the "x-oss-meta-" prefix is also added to the user metadata key. 
                put.addHeader("x-oss-meta-"+meta.getKey().toString(), meta.getValue().toString());
            }

            httpClient = HttpClients.createDefault();

            response = httpClient.execute(put);

            System.out.println("Status code of the upload: "+response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() == 200){
                System.out.println("The object is uploaded by using the library.");
            }
            System.out.println(response.toString());
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            response.close();
            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 local file.
	file, err := os.Open(filePath)
	if err != nil {
		return err
	}
	defer file.Close()

	// Read the object 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
	}

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

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

	// Send a 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: %d\n", resp.StatusCode)
	if resp.StatusCode == 200 {
		fmt.Println("The object is uploaded by using the library.")
	} else {
		fmt.Println("Upload failed")
	}
	body, _ := ioutil.ReadAll(resp.Body)
	fmt.Println(string(body))

	return nil
}

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

	// 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. 
	filePath := "C:\\Users\\demo.txt"

	// Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned URL was generated. 
	headers := map[string]string{
		"Content-Type": "text/plain;charset=utf8",
		"x-oss-storage-class": "Standard",
	}

	// Specify user metadata. Make sure that the user metadata here is the same as the user metadata specified when the presigned 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 an object to OSS. 

    :param signed_url: the presigned URL. 
    :param file_path: the full path of the local file that you want to upload. 
    :param headers: request headers. This parameter is optional. 
    :param metadata: user metadata. This parameter is optional. 
    :return: None
    """
    if not headers:
        headers = {}
    if not metadata:
        metadata = {}

    # Add the x-oss-meta- prefix to the metadata key.
    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: {response.status_code}")
            if response.status_code == 200:
                print("The object is uploaded by using the 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 generated signed URL. 
    signed_url = "<signedUrl>"
   
    # Specify the full path of the local file. By default, if you do not specify the full path of the local file, the local file is uploaded from the directory in which the script is stored. 
    file_path = "C:\\Users\\demo.txt"

    # Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned URL was generated. 
    headers = {
         "Content-Type": "text/plain;charset=utf8",
         "x-oss-storage-class": "Standard"
    }

    # Specify user metadata. Make sure that the user metadata is the same as the user metadata specified when the pesigned 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 {
        // Add the x-oss-meta- prefix to the metadata keys.
        for (const [key, value] of Object.entries(metadata)) {
            headers[`x-oss-meta-${key}`] = value;
        }

        // Create a readable stream.
        const fileStream = fs.createReadStream(filePath);

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

        console.log(`Status code: ${response.status}`);
        if (response.status === 200) {
            console.log("The object is uploaded by using the library.");
        } else {
            console.log("Upload failed.");
        }
        console.log(response.data);
    } catch (error) {
        console.error(`An error occurred: ${error.message}`);
    }
}

// Specify the main function.
(async () => {
    // Replace <signedUrl> with the presigned URL. 
    const signedUrl = "<signedUrl>";

    // Specify the full path of the local file that you want to upload. By default, if you do not specify the full path of the local file, the local file is uploaded from the directory in which the script is stored. 
    const filePath = "C:\\Users\\demo.txt";

    // Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned URL was generated. 
    const headers = {
         "Content-Type": "text/plain;charset=utf8",
         "x-oss-storage-class": "Standard"
    };

    // Specify user metadata. Make sure that the user metadata here is the same as the user metadata specified when the presigned 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</h1>

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

    <script>
        // Replace <signedUrl> 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++

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

// Specify the callback function that is used to process 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) {
        // Specify the presigned 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 local file.
        FILE* file = fopen(filePath.c_str(), "rb");
        if (!file) {
            std::cerr << "Unable to open the file: " << filePath << std::endl;
            return;
        }

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

        // Configure a file read callback.
        curl_easy_setopt(curl, CURLOPT_READDATA, file);
        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fileSize);

        // Specify 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);

        // Specify the callback function that is used to process the response.
        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: " << responseCode << std::endl;
            if (responseCode == 200) {
                std::cout << "The object is uploaded by using the network library." << std::endl;
            } else {
                std::cout << "Upload failed." << std::endl;
            }
            std::cout << readBuffer << std::endl;
        }

        // Clear the cURL handle.
        fclose(file);
        curl_slist_free_all(chunk);
        curl_easy_cleanup(curl);
    }

    curl_global_cleanup();
}

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

    // 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. 
    std::string filePath = "C:\\Users\\demo.txt";

    // Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned URL was generated. 
    std::map<std::string, std::string> headers = {
         {"Content-Type", "text/plain;charset=utf8"},
         {"x-oss-storage-class", "Standard"}
    };

    // Specify user metadata. Make sure that the user metadata here is the same as the user metadata specified when the presigned 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 presigned URL. 
        String signedUrl = "<signedUrl>";

        // 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. 
        String pathName = "/storage/emulated/0/demo.txt";

        // Specify request headers. Make sure that the values of the request headers are the same as those specified when the presigned URL was generated. 
        Map<String, String> headers = new HashMap<>();
        headers.put("Content-Type", "text/plain;charset=utf8");
        headers.put("x-oss-storage-class", "Standard");

        // Specify user metadata. Make sure that the user metadata here is the same as the user metadata specified when the presigned 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);

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

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

                // Read the local 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();

                // Obtain the response.
                int responseCode = connection.getResponseCode();
                Log.d(TAG, "Status code: " + responseCode);
                if (responseCode == 200) {
                    Log.d(TAG, "The object is uploaded by using the 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, "Object uploaded", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(SignUrlUploadActivity.this, "Upload failed", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

FAQ

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

If the server receives the request and verifies the signature, the file upload does not fail.

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?

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 example.