Upload an Object Using a Presigned URL (AWS SDK for Java)

You can use the AWS SDK for Java to generate a presigned URL that you, or anyone you give the URL, can use to upload an object to Amazon S3. When you use the URL to upload an object, Amazon S3 creates the object in the specified bucket. If an object with the same key that is specified in the presigned URL already exists in the bucket, Amazon S3 replaces the existing object with the uploaded object. To successfully complete an upload, you must do the following:

• Specify the HTTP PUT verb when creating the GeneratePresignedUrlRequest and HttpURLConnection objects.
• Interact with the HttpURLConnection object in some way after finishing the upload. The following example accomplishes this by using the HttpURLConnection object to check the HTTP response code.

Example
This example generates a presigned URL and uses it to upload sample data as an object. For instructions on creating and testing a working sample, see Testing the Amazon S3 Java Code Examples.

import com.amazonaws.AmazonServiceException;

import com.amazonaws.HttpMethod;

import com.amazonaws.SdkClientException;

import com.amazonaws.auth.profile.ProfileCredentialsProvider;

import com.amazonaws.regions.Regions;

import com.amazonaws.services.s3.AmazonS3;

import com.amazonaws.services.s3.AmazonS3ClientBuilder;

import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;

import com.amazonaws.services.s3.model.S3Object;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.net.HttpURLConnection;

import java.net.URL;

public class GeneratePresignedUrlAndUploadObject {

public static void main(String[] args) throws IOException {

Regions clientRegion = Regions.DEFAULT_REGION;

String bucketName = "*** Bucket name ***";

String objectKey = "*** Object key ***";

try {

AmazonS3 s3Client = AmazonS3ClientBuilder.standard()

.withCredentials(new ProfileCredentialsProvider())

.withRegion(clientRegion)

.build();

// Set the pre-signed URL to expire after one hour.

java.util.Date expiration = new java.util.Date();

long expTimeMillis = expiration.getTime();

expTimeMillis += 1000 * 60 * 60;

expiration.setTime(expTimeMillis);

// Generate the pre-signed URL.

System.out.println("Generating pre-signed URL.");

GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(bucketName, objectKey)

.withMethod(HttpMethod.PUT)

.withExpiration(expiration);

URL url = s3Client.generatePresignedUrl(generatePresignedUrlRequest);

// Create the connection and use it to upload the new object using the pre-signed URL.

HttpURLConnection connection = (HttpURLConnection) url.openConnection();

connection.setDoOutput(true);

connection.setRequestMethod("PUT");

OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());

out.write("This text uploaded as an object via presigned URL.");

out.close();

// Check the HTTP response code. To complete the upload and make the object available,

// you must interact with the connection object in some way.

connection.getResponseCode();

System.out.println("HTTP response code: " + connection.getResponseCode());

// Check to make sure that the object was uploaded successfully.

S3Object object = s3Client.getObject(bucketName, objectKey);

System.out.println("Object " + object.getKey() + " created in bucket " + object.getBucketName());

} catch (AmazonServiceException e) {

// The call was transmitted successfully, but Amazon S3 couldn't process

// it, so it returned an error response.

e.printStackTrace();

} catch (SdkClientException e) {

// Amazon S3 couldn't be contacted for a response, or the client

// couldn't parse the response from Amazon S3.

e.printStackTrace();

}

}

}