Use a presigned URL to upload an object - Object Storage Service: Central de Documentação do Alibaba Cloud

Por padrão, a lista de controle de acesso (ACL) de um objeto em um bucket do Object Storage Service (OSS) é privada. Somente o proprietário do objeto tem permissão para acessá-lo. Com o OSS SDK for Python, você gera uma URL pré-assinada e a compartilha com um usuário para permitir o upload de um objeto. Ao gerar essa URL, especifique o período de validade para limitar o tempo disponível para upload. Enquanto a URL pré-assinada estiver válida, o usuário poderá usá-la para enviar objetos ao bucket quantas vezes for necessário. Após o término da validade, o upload não será mais permitido e você deverá gerar uma nova URL pré-assinada.

Observações de uso

Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter detalhes sobre as regiões e endpoints suportados, consulte Regiões e endpoints.
As credenciais de acesso neste exemplo são obtidas de variáveis de ambiente. Para mais informações sobre como configurar as credenciais de acesso, consulte Configurar credenciais de acesso (Python SDK V1).
Uma instância OSSClient é criada aqui usando um endpoint do OSS. Caso precise criar uma instância OSSClient com nomes de domínio personalizados ou Security Token Service (STS), consulte Inicialização.
A geração de uma URL pré-assinada não exige permissões específicas. No entanto, terceiros só conseguirão fazer upload de arquivos com sucesso se você possuir a permissão oss:PutObject. Para mais detalhes, consulte Conceder uma política de acesso personalizada a um usuário RAM.
O algoritmo de assinatura V4 é utilizado neste tópico para gerar URLs pré-assinadas com validade de até 7 dias. Para saber mais, consulte (Recomendado) Assinaturas V4 em URLs pré-assinadas.

Processo

A figura a seguir ilustra como usar uma URL pré-assinada que permite requisições HTTP PUT para fazer upload de um objeto no OSS.

Código de exemplo

O proprietário do objeto gera uma URL pré-assinada que autoriza requisições HTTP PUT.

# -*- 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)

Um usuário usa a URL pré-assinada com permissão HTTP PUT para enviar o objeto.

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

Importante

Se ocorrer um erro 403 de incompatibilidade de assinatura ao usar Node.js para upload, geralmente isso acontece porque o cabeçalho de requisição Content-Type foi definido explicitamente, mas não estava incluído na geração da URL pré-assinada. Essa divergência causa falha na verificação da assinatura. Para resolver, evite definir o cabeçalho Content-Type na requisição de upload ou inclua-o ao gerar a URL pré-assinada.

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);

        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

Importante

Ao encontrar um erro 403 de incompatibilidade de assinatura com Browser.js, verifique se o navegador adicionou automaticamente o cabeçalho Content-Type sem que este estivesse presente na geração da URL pré-assinada. Tal inconsistência provoca falha na validação da assinatura. A solução consiste em especificar o cabeçalho Content-Type no momento da criação da URL pré-assinada.

<!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);
    }
}

Cenários comuns

Usar uma URL pré-assinada com cabeçalhos de requisição e metadados de usuário específicos para fazer upload de um objeto

O proprietário do objeto gera uma URL pré-assinada contendo cabeçalhos de requisição e metadados de usuário específicos, permitindo requisições HTTP PUT.

# -*- 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)

O usuário usa a URL pré-assinada com suporte a HTTP PUT para fazer upload do objeto.

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

Importante

Caso enfrente um erro 403 de incompatibilidade de assinatura ao usar Browser.js, normalmente o motivo é a adição automática do cabeçalho Content-Type pelo navegador, ausente na geração da URL pré-assinada. Essa discrepância invalida a verificação da assinatura. Para corrigir, defina o cabeçalho Content-Type durante a geração da URL pré-assinada.

<!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();
            }
        }
    }
}

Perguntas frequentes

Ao usar uma URL pré-assinada para enviar um arquivo local, o upload é concluído se a URL expirar durante a transferência?

Se o servidor já tiver recebido a requisição e validado a assinatura antes da expiração, o upload do arquivo será concluído com sucesso.

Caso eu não defina cabeçalhos de requisição e metadados de usuário ao gerar a URL, preciso especificá-los ao usá-la para fazer upload de um arquivo local?

Não é obrigatório informar cabeçalhos de requisição nem metadados de usuário, pois são parâmetros opcionais. Se não precisar deles, basta remover o código correspondente dos exemplos anteriores.