Object Storage Service:Share objects with object URLs

Generate a signed URL used to download an object.

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.model.GeneratePresignedUrlRequest;
import java.net.URL;
import java.util.Date;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 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. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the full path of the object. Example: exampleobject.txt. Do not include the bucket name in the full path of the object. 
        String objectName = "exampleobject.txt";

        // Create an OSSClient instance. 
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        URL signedUrl = null;
        try {
            // Specify the validity period of the signed URL. Unit: milliseconds. In this example, the validity period is set to 1 hour. 
            Date expiration = new Date(new Date().getTime() + 3600 * 1000L);

            // Create a request to generate a signed URL. 
            GeneratePresignedUrlRequest request = new GeneratePresignedUrlRequest(bucketName, objectName, HttpMethod.GET);
            // Set the validity period of the signed URL. 
            request.setExpiration(expiration);

            // Generate the signed URL that allows HTTP GET requests. 
            signedUrl = ossClient.generatePresignedUrl(request);
            // Display the signed URL. 
            System.out.println("signed url for getObject: " + signedUrl);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        }
    }
}

Use the signed URL to download the object.

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import java.io.*;
import java.util.*;

public class Get1 {
    public static void main(String[] args) throws Throwable {        
        // Specify the full path of the local file to which you want to download the object. 
        String pathName = "D:\\example.jpg";
        // Enter the signed URL generated in Step 1. 
        String signedUrl= "yourSignedUrl";

        Map<String, String> headers = new HashMap<String, String>();
        Map<String, String> userMetadata = new HashMap<String, String>();

        // Use the signed URL to download the object. In this example, HttpClients is used. 
        getObjectWithHttp(signedUrl, pathName, headers, userMetadata);
    }

    public static void getObjectWithHttp(String signedUrl, String pathName, Map<String, String> headers, Map<String, String> userMetadata) throws IOException {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse response = null;
        try {
            HttpGet get = new HttpGet(signedUrl);

            // If headers, such as metadata headers and the header that indicates the storage class, are specified during URL generation, you must send these headers to the server when you use the signed URL to download the object. If headers that are sent to the server for the signature calculation are inconsistent with those specified during URL generation, a signature error is reported. 
            for(Map.Entry header: headers.entrySet()){
                get.addHeader(header.getKey().toString(),header.getValue().toString());
            }
            for(Map.Entry meta: userMetadata.entrySet()){
                // If userMeta is used, the x-oss-meta- prefix is added to userMeta. When you use other methods to generate a signed URL for object download, the x-oss-meta- prefix is also added to userMeta. 
                get.addHeader("x-oss-meta-"+meta.getKey().toString(), meta.getValue().toString());
            }

            httpClient = HttpClients.createDefault();
            response = httpClient.execute(get);

            System.out.println("Download status code: "+response.getStatusLine().getStatusCode());
            if(response.getStatusLine().getStatusCode() == 200){
                System.out.println("The object is downloaded by using the network library");
            }
            System.out.println(response.toString());

            saveFileToLocally(response.getEntity().getContent(), pathName);
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            response.close();
            httpClient.close();
        }
    }

    public static void saveFileToLocally(InputStream inputStream, String pathName) throws IOException {
        DataInputStream in = null;
        OutputStream out = null;
        try {
            in = new DataInputStream(inputStream);
            out = new DataOutputStream(new FileOutputStream(pathName));
            int bytes = 0;
            byte[] bufferOut = new byte[1024];
            while ((bytes = in.read(bufferOut)) != -1) {
                out.write(bufferOut, 0, bytes);
            }
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            in.close();
            out.close();
        }
    }
}

Generate a signed URL used to download an object.

<?php
if (is_file(__DIR__ . '/../autoload.php')) {
    require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
    require_once __DIR__ . '/../vendor/autoload.php';
}
use OSS\Credentials\EnvironmentVariableCredentialsProvider; 
use OSS\OssClient;
use OSS\Core\OssException;
use OSS\Http\RequestCore;
use OSS\Http\ResponseCore;
 
// 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 = new 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 name of the bucket. Example: examplebucket. 
$bucket= "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path of the object. 
$object = "exampleobject.txt";
// Set the validity period of the signed URL to 3,600 seconds. 
$timeout = 3600;
// Generate a signed URL that is used to download the object. 
$options = array(
    "response-content-disposition"=>"attachment",
);
try {
    $config = array(
        "provider" => $provider,
        "endpoint" => $endpoint,        
    );
    $ossClient = new OssClient($config);
    $signedUrl = $ossClient->signUrl($bucket, $object, $timeout,'GET',$options);
 
} catch (OssException $e) {
    printf(__FUNCTION__ . ": FAILED\n");
    printf($e->getMessage() . "\n");
    return;
}
print(__FUNCTION__ . ": signedUrl: " . $signedUrl . "\n");

Use the signed URL to download the object.

<?php

if (is_file(__DIR__ . '/../autoload.php')) {
    require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
    require_once __DIR__ . '/../vendor/autoload.php';
}

use OSS\Http\RequestCore;
use OSS\Http\ResponseCore;
// Enter the signed URL generated in Step 1. 
$signedUrl = 'yourSignedUrl';
// Specify the full path of the local file to which you want to download the object. 
$localfile = "D://example.txt";
// Use the signed URL to download the object. 
$request = new RequestCore($signedUrl);
// Set the default method that is used to access the signed URL to GET. 
$request->set_method('GET');
$request->add_header('Content-Type', '');
$request->send_request();
$res = new ResponseCore($request->get_response_header(), $request->get_response_body(), $request->get_response_code());
if ($res->isOK()) {
    print(__FUNCTION__ . ": OK" . "\n");
	 file_put_contents($localfile,$request->get_response_body());
} else {
    print(__FUNCTION__ . ": FAILED" . "\n");
};   

Generate a signed URL used to download an object.

const OSS = require("ali-oss");
const client = new OSS({
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
  region: "oss-cn-hangzhou",
  // 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. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  // Specify the name of the bucket. Example: examplebucket. 
  bucket: "examplebucket",
});
// Generate a signed URL used to download the object. 
const url = client.signatureUrl("exampleobject.txt");
console.log(url);

Use the signed URL to download the object.

const axios = require("axios");
const fs = require("fs");
// Enter the signed URL generated in Step 1. 
const url = "yourSignedUrl";
// Specify the full path of the local file to which you want to download the object. 
const file = "D://example.txt";

axios
  // Set the response type to arraybuffer. 
  .get(url, { responseType: "arraybuffer" }) 
  .then((response) => {
    fs.writeFile(file, response.data, (err) => {
      if (err) {
        console.log(err);
      } else {
        console.log("The object is downloaded.");
      }
    });
  })
  .catch((error) => {
    console.log(error);
  });

Generate a signed URL used to download an object.

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

# 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.ProviderAuth(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. 
# Specify the name of the bucket. Example: examplebucket. 
bucket = oss2.Bucket(auth, 'https://oss-cn-hangzhou.aliyuncs.com', 'examplebucket')
# Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
object_name = 'exampleobject.txt'

# Set the validity period of the signed URL to 3,600 seconds. 
# Set the slash_safe parameter to True to prevent OSS from identifying the forward slashes (/) in the full path of the object as escape characters. This allows you to use the generated signed URL to download the object. 
url = bucket.sign_url('GET', object_name, 3600, slash_safe=True)
print('The signed URL:', url) 

Use the signed URL to download the object.

# -*- coding: utf-8 -*-
import oss2
import requests
# Enter the signed URL generated in Step 1. 
url = 'yourSignedUrl'

# Use the signed URL to download the object. In this example, the requests module is used. 
resp = requests.get(url)

# Specify the local path to which you want to download the object. 
with open("D:\\examplefile.txt", "wb") as code:
    code.write(resp.content)

Generate a signed URL used to download an object.

const OSS = require("ali-oss");
const STS = require("ali-oss").STS;
// const cors = require("cors");

const stsClient = new STS({
  // 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. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
});
// Specify the name of the bucket. Example: examplebucket. 
const bucket = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
const region = "oss-cn-hangzhou";
// Specify the Alibaba Cloud Resource Name (ARN) of the RAM role. 
const roleArn = "acs:ram::137918634953****:role/ossram";
const getSts = () => {
  stsClient
    .assumeRole(
      roleArn,
      `{
        "Statement": [
          {
            "Effect": "Allow",
            "Action": "*",
            "Resource": [
              "acs:oss:*:*:examplebucket/*"
            ]
          }
        ]
      }`,
      3000 // Specify the validity period of the security token. Unit: seconds. 
    )
    .then((r) => {
      console.log("send:", r.credentials);
      const { SecurityToken, AccessKeyId, AccessKeySecret } = r.credentials;
      const client = new OSS({
        bucket,
        region,
        accessKeyId: AccessKeyId,
        accessKeySecret: AccessKeySecret,
        stsToken: SecurityToken,
        refreshSTSTokenInterval: 9000,
      });
      // Generate the signed URL that is used to download the object. 
      const url = client.asyncSignatureUrl("exampleobject.txt", {
        expires: 3600,
        method: "GET",
      });
      console.log("url:", url);
      // client.get("exampleobject.txt", Buffer.from("body")).then((res) => {
      //   console.log("res", res.url);
      // });
    });
};
getSts();

Use the signed URL to download the object.

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Document</title>
  </head>
  <body>
    <script src="https://gosspublic.alicdn.com/aliyun-oss-sdk-6.18.0.min.js"></script>
    <script>
      // Enter the signed URL generated in Step 1. 
      const url = "yourSignedUrl";
      var xhr = new XMLHttpRequest();
      xhr.open("GET", url, true);
      // Set the response type to blob. 
      xhr.responseType = "blob"; 
      xhr.onload = function () {
        if (xhr.status === 200) {
          const blob = xhr.response;
          const reader = new FileReader();
          reader.onloadend = function () {
            const fileData = reader.result;
            // Specify the name of the downloaded object. 
            const file = new File([fileData], "examplefile.txt");
            const a = document.createElement("a");
            a.href = URL.createObjectURL(file);
            a.download = file.name;
            a.click();
          };
          reader.readAsArrayBuffer(blob);
        } else {
          console.log("The request failed.");
        }
      };
      xhr.send();
    </script>
  </body>
</html>

Generate a signed URL used to download an object.

// Specify the name of the bucket. Example: examplebucket. 
String bucketName = "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path. Example: exampleobject.txt. 
String objectKey = "exampleobject.txt";
String url = null;
try {
    // Generate a signed URL to download the object. 
    GeneratePresignedUrlRequest request = new GeneratePresignedUrlRequest(bucketName, objectKey);
    // Set the validity period of the signed URL to 30 minutes. 
    request.setExpiration(30*60);
    request.setMethod(HttpMethod.GET);
    url = oss.presignConstrainedObjectURL(request);
    Log.d("url", url);
} catch (ClientException e) {
    e.printStackTrace();
}

Use the signed URL to download the object.

// Enter the generated signed URL. 
String url = "";
OkHttpClient client = new OkHttpClient();
// Use the signed URL to download an object. 
Request getRequest = new Request.Builder()
        .url(url)
        .get()
        .build();
client.newCall(getRequest).enqueue(new Callback() {
    @Override
    public void onFailure(Call call, IOException e) {
        e.printStackTrace();
    }

    @Override
    public void onResponse(Call call, Response response) throws IOException {
        if (response.code() == 203 || response.code() >= 300) {
            Log.d("download", "fail");
            Log.d("download", response.body().string());
            return;
        }
        // The object is downloaded. 
        InputStream inputStream = response.body().byteStream();

        byte[] buffer = new byte[2048];
        int len;

        while ((len = inputStream.read(buffer)) != -1) {
            // Process the downloaded data. For example, display the image or perform a write operation on the object. 
        }
    }
});

Generate a signed URL used to download an object.

package main

import (
    "fmt"
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
    "os"
)

func HandleError(err error) {
    fmt.Println("Error:", err)
    os.Exit(-1)
}

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 {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }
    // 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 your actual endpoint. 
    client, err := oss.New("yourEndpoint", "", "", oss.SetCredentialsProvider(&provider))
    if err != nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Specify the name of the bucket. Example: examplebucket. 
    bucketName := "examplebucket"
    // Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path of the object. 
    objectName := "exampledir/exampleobject.txt"
    // Download the object to the specified path on your local computer. If a file that has the same name already exists in the path, the downloaded object overwrites the file. Otherwise, the downloaded object is saved in the path. 
    bucket, err := client.Bucket(bucketName)
    if err != nil {
        HandleError(err)
    }

    // Generate a signed URL that has a specific validity period for downloading the object. In this example, the validity period of the URL is 60 seconds. 
    signedURL, err := bucket.SignURL(objectName, oss.HTTPGet, 60)
    if err != nil {
        HandleError(err)
    }
    fmt.Printf("Sign Url:%s\n", signedURL)
}

Use the signed URL to download the object.

package main

import (
	"fmt"
	"os"
	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
    // 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 your actual endpoint. 
	client, err := oss.New("https://oss-cn-hangzhou.aliyuncs.com", "", "")
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	
  	// Specify the name of the bucket. Example: examplebucket. 
  	bucketName := "examplebucket"
  	// Specify the full path of the local file to which you want to download the object. 
  	localDownloadedFilename := "D://example.txt"
  
  	bucket, err := client.Bucket(bucketName)
  	if err != nil {
    	HandleError(err)
  	}
  	// Enter the signed URL generated in Step 1. 
  	signedURL := "yourSignedUrl"
  	// Use the generated signed URL to download the object to a local path. 
  	err = bucket.GetObjectToFileWithURL(signedURL, localDownloadedFilename)
  	if err != nil {
    	HandleError(err)
  	}
}

func HandleError(err error) {
	fmt.Println("Error:", err)
	os.Exit(-1)
}

Generate a signed URL used to download an object.

// Specify the name of the bucket. 
NSString *bucketName = @"examplebucket";
// Specify the name of the object. 
NSString *objectKey = @"exampleobject.txt";
__block NSString *urlString;
// Generate a signed URL with a specified validity period for downloading the object. In this example, the validity period of the URL is 30 minutes. 
OSSTask *task = [client presignConstrainURLWithBucketName:bucketName
                                            withObjectKey:objectKey
                                               httpMethod:@"GET"
                                   withExpirationInterval:30 * 60
                                           withParameters:@{}];
[task continueWithBlock:^id _Nullable(OSSTask * _Nonnull task) {
    if (task.error) {
        NSLog(@"presign error: %@", task.error);
    } else {
        urlString = task.result;
        NSLog(@"url: %@", urlString);
    }
    return nil;
}];

Use the signed URL to download the object.

// Use the signed URL to download the object. 
NSURL * url = [NSURL URLWithString:urlString];
NSURLRequest * request = [NSURLRequest requestWithURL:url];
NSURLSession * session = [NSURLSession sharedSession];
NSURLSessionTask * sessionTask = [session dataTaskWithRequest:request
                                            completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
    if (error) {
        NSLog(@"download error: %@", error);
        return;
    } else if (((NSHTTPURLResponse*)response).statusCode == 203 ||
               ((NSHTTPURLResponse*)response).statusCode >= 300) {
        NSString *body = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        NSLog(@"download error: %@", body);
        return;
    }
    NSLog(@"download success");
}];
[sessionTask resume];