Help Center> Object Storage Service> Android> Object Upload> Performing a Browser-Based Upload
Updated on 2023-11-09 GMT+08:00
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Performing a Browser-Based Upload

If you have any questions during development, post them on the Issues page of GitHub. For details about parameters and usage of each API, see the API Reference

Performing a browser-based upload is to upload objects to a specified bucket in HTML form. The maximum size of an object is 5 GB.

You can call ObsClient.createPostSignature to generate request parameters for browser-based upload. You can use code to simulate a browser-based upload. For details, see PostObjectSample. You can also perform a browser-based upload.

  1. Call ObsClient.createPostSignature to generate request parameters for authentication.
  2. Prepare an HTML form page.
  3. Enter the request parameters in the HTML page.
  4. Select a local file and upload it in browser-based mode.

There are two request parameters generated:

  • policy, which corresponds to the policy field in the form
  • signature: corresponds to the signature field in the form.

The following sample code shows how to generate the parameters in a browser-based upload request.

// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an ObsClient instance.
final ObsClient obsClient = new ObsClient(ak, sk, endPoint);

PostSignatureRequest request = new PostSignatureRequest();
// Fill in parameters in the form.
Map<String, Object> formParams = new HashMap<String, Object>();
// Set the object ACL to public-read.
formParams.put("x-obs-acl", "public-read");
// Set the MIME type for the object.
formParams.put("content-type", "text/plain");

request.setFormParams(formParams);
// Set the validity period for the browser-based upload request, in seconds.
request.setExpires(3600);
PostSignatureResponse response = obsClient.createPostSignature(request);

// Obtain the request parameters.
Log.i("CreatePostSignature", "\t" + response.getPolicy());
Log.i("CreatePostSignature", "\t" + response.getSignature());

Code of an HTML form example is as follows:

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>

<form action="http://bucketname.your-endpoint/" method="post" enctype="multipart/form-data">
Object key
<!-- Object name -->
<input type="text" name="key" value="objectname" />
<p>
ACL
<!-- Object ACL -->
<input type="text" name="x-obs-acl" value="public-read" />
<p>
Content-Type
<!-- Object MIME type -->
<input type="text" name="content-type" value="text/plain" />
<p>
<!-- Base64 code of the policy -->
<input type="hidden" name="policy" value="*** Provide your policy ***" />
<!-- AK -->
<input type="hidden" name="AccessKeyId" value="*** Provide your access key ***"/>
<!-- Signature information -->
<input type="hidden" name="signature" value="*** Provide your signature ***"/>

<input name="file" type="file" />
<input name="submit" value="Upload" type="submit" />
</form>
</body>
</html>
  • Values of policy and signature in the HTML form are obtained from the returned result of ObsClient.createPostSignature.
  • You can directly download the HTML form example: PostDemo.
Parent topic: Object Upload