Parse Amazon S3 URIs using an AWS SDK

The following code example shows how to parse Amazon S3 URIs to extract important components like the bucket name and object key.

Java

SDK for Java 2.x

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

Parse an Amazon S3 URI by using the S3Uri class.

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.S3Uri;
import software.amazon.awssdk.services.s3.S3Utilities;

import java.net.URI;
import java.util.List;
import java.util.Map;

    /**
     *
     * @param s3Client    - An S3Client through which you acquire an S3Uri instance.
     * @param s3ObjectUrl - A complex URL (String) that is used to demonstrate S3Uri
     *                    capabilities.
     */
    public static void parseS3UriExample(S3Client s3Client, String s3ObjectUrl) {
        logger.info(s3ObjectUrl);
        // Console output:
        // 'https://s3.us-west-1.amazonaws.com/myBucket/resources/doc.txt?versionId=abc123&partNumber=77&partNumber=88'.

        // Create an S3Utilities object using the configuration of the s3Client.
        S3Utilities s3Utilities = s3Client.utilities();

        // From a String URL create a URI object to pass to the parseUri() method.
        URI uri = URI.create(s3ObjectUrl);
        S3Uri s3Uri = s3Utilities.parseUri(uri);

        // If the URI contains no value for the Region, bucket or key, the SDK returns
        // an empty Optional.
        // The SDK returns decoded URI values.

        Region region = s3Uri.region().orElse(null);
        log("region", region);
        // Console output: 'region: us-west-1'.

        String bucket = s3Uri.bucket().orElse(null);
        log("bucket", bucket);
        // Console output: 'bucket: myBucket'.

        String key = s3Uri.key().orElse(null);
        log("key", key);
        // Console output: 'key: resources/doc.txt'.

        Boolean isPathStyle = s3Uri.isPathStyle();
        log("isPathStyle", isPathStyle);
        // Console output: 'isPathStyle: true'.

        // If the URI contains no query parameters, the SDK returns an empty map.
        Map<String, List<String>> queryParams = s3Uri.rawQueryParameters();
        log("rawQueryParameters", queryParams);
        // Console output: 'rawQueryParameters: {versionId=[abc123], partNumber=[77,
        // 88]}'.

        // Retrieve the first or all values for a query parameter as shown in the
        // following code.
        String versionId = s3Uri.firstMatchingRawQueryParameter("versionId").orElse(null);
        log("firstMatchingRawQueryParameter-versionId", versionId);
        // Console output: 'firstMatchingRawQueryParameter-versionId: abc123'.

        String partNumber = s3Uri.firstMatchingRawQueryParameter("partNumber").orElse(null);
        log("firstMatchingRawQueryParameter-partNumber", partNumber);
        // Console output: 'firstMatchingRawQueryParameter-partNumber: 77'.

        List<String> partNumbers = s3Uri.firstMatchingRawQueryParameters("partNumber");
        log("firstMatchingRawQueryParameter", partNumbers);
        // Console output: 'firstMatchingRawQueryParameter: [77, 88]'.

        /*
         * Object keys and query parameters with reserved or unsafe characters, must be
         * URL-encoded.
         * For example replace whitespace " " with "%20".
         * Valid:
         * "https://s3.us-west-1.amazonaws.com/myBucket/object%20key?query=%5Bbrackets%5D"
         * Invalid:
         * "https://s3.us-west-1.amazonaws.com/myBucket/object key?query=[brackets]"
         * 
         * Virtual-hosted-style URIs with bucket names that contain a dot, ".", the dot
         * must not be URL-encoded.
         * Valid: "https://my.Bucket.s3.us-west-1.amazonaws.com/key"
         * Invalid: "https://my%2EBucket.s3.us-west-1.amazonaws.com/key"
         */
    }

    private static void log(String s3UriElement, Object element) {
        if (element == null) {
            logger.info("{}: {}", s3UriElement, "null");
        } else {
            logger.info("{}: {}", s3UriElement, element.toString());
        }
    }