S3 URI Parser

.changes/next-release/feature-AmazonS3-92ece24.json

@@ -0,0 +1,6 @@
+{
+    "category": "Amazon S3", 
+    "contributor": "", 
+    "type": "feature", 
+    "description": "Adding feature for parsing S3 URIs"
+}

services/s3/src/main/java/software/amazon/awssdk/services/s3/S3Utilities.java

@@ -20,10 +20,14 @@
 import java.net.URI;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import software.amazon.awssdk.annotations.Immutable;
 import software.amazon.awssdk.annotations.SdkInternalApi;
 import software.amazon.awssdk.annotations.SdkPublicApi;
@@ -62,8 +66,11 @@
 import software.amazon.awssdk.services.s3.internal.endpoints.UseGlobalEndpointResolver;
 import software.amazon.awssdk.services.s3.model.GetObjectRequest;
 import software.amazon.awssdk.services.s3.model.GetUrlRequest;
+import software.amazon.awssdk.services.s3.parsing.S3Uri;
 import software.amazon.awssdk.utils.AttributeMap;
+import software.amazon.awssdk.utils.StringUtils;
 import software.amazon.awssdk.utils.Validate;
+import software.amazon.awssdk.utils.http.SdkHttpUtils;
 
 /**
  * Utilities for working with Amazon S3 objects. An instance of this class can be created by:
@@ -94,7 +101,7 @@
 @SdkPublicApi
 public final class S3Utilities {
     private static final String SERVICE_NAME = "s3";
-
+    private static final Pattern ENDPOINT_PATTERN = Pattern.compile("^(.+\\.)?s3[.-]([a-z0-9-]+)\\.");
     private final Region region;
     private final URI endpoint;
     private final S3Configuration s3Configuration;
@@ -251,6 +258,162 @@ public URL getUrl(GetUrlRequest getUrlRequest) {
         }
     }
 
+    /**
+     * Returns a parsed {@link S3Uri} with which a user can easily retrieve the bucket, key, region, style, and query
+     * parameters of the URI. Only path-style and virtual-hosted-style URI parsing is supported, including CLI-style
+     * URIs, e.g., "s3://bucket/key". AccessPoints and Outposts URI parsing is not supported. If you work with object keys
+     * and/or query parameters with special characters, they must be URL-encoded, e.g., replace " " with "%20". If you work with
+     * virtual-hosted-style URIs with bucket names that contain a dot, i.e., ".", the dot must not be URL-encoded. Encoded
+     * buckets, keys, and query parameters will be returned decoded.
+     *
+     * <p>
+     * For more information on path-style and virtual-hosted-style URIs, see <a href=
+     * "https://docs.aws.amazon.com/AmazonS3/latest/userguide/access-bucket-intro.html"
+     * >Methods for accessing a bucket</a>.
+     *
+     * @param uri The URI to be parsed
+     * @return Parsed {@link S3Uri}
+     *
+     * <p><b>Example Usage</b>
+     * <p>
+     * {@snippet :
+     *     S3Client s3Client = S3Client.create();
+     *     S3Utilities s3Utilities = s3Client.utilities();
+     *     String uriString = "https://myBucket.s3.us-west-1.amazonaws.com/doc.txt?versionId=abc123";
+     *     URI uri = URI.create(uriString);
+     *     S3Uri s3Uri = s3Utilities.parseUri(uri);
+     *
+     *     String bucket = s3Uri.bucket().orElse(null); // "myBucket"
+     *     String key = s3Uri.key().orElse(null); // "doc.txt"
+     *     Region region = s3Uri.region().orElse(null); // Region.US_WEST_1
+     *     boolean isPathStyle = s3Uri.isPathStyle(); // false
+     *     String versionId = s3Uri.firstMatchingRawQueryParameter("versionId").orElse(null); // "abc123"
+     *}
+     */
+    public S3Uri parseUri(URI uri) {
+        validateUri(uri);
+
+        if ("s3".equalsIgnoreCase(uri.getScheme())) {
+            return parseAwsCliStyleUri(uri);
+        }
+
+        return parseStandardUri(uri);
+    }
+
+    private S3Uri parseStandardUri(URI uri) {
+
+        if (uri.getHost() == null) {
+            throw new IllegalArgumentException("Invalid S3 URI: no hostname: " + uri);
+        }
+
+        Matcher matcher = ENDPOINT_PATTERN.matcher(uri.getHost());
+        if (!matcher.find()) {
+            throw new IllegalArgumentException("Invalid S3 URI: hostname does not appear to be a valid S3 endpoint: " + uri);
+        }
+
+        S3Uri.Builder builder = S3Uri.builder().uri(uri);
+        addRegionIfNeeded(builder, matcher.group(2));
+        addQueryParamsIfNeeded(builder);
+
+        String prefix = matcher.group(1);
+        if (StringUtils.isEmpty(prefix)) {
+            return parsePathStyleUri(builder);
+        }
+        return parseVirtualHostedStyleUri(builder, matcher);
+    }
+
+    private S3Uri.Builder addRegionIfNeeded(S3Uri.Builder builder, String region) {
+        if (!"amazonaws".equals(region)) {
+            return builder.region(Region.of(region));
+        }
+        return builder;
+    }
+
+    private S3Uri.Builder addQueryParamsIfNeeded(S3Uri.Builder builder) {
+        if (builder.uri().getQuery() != null) {
+            return builder.queryParams(SdkHttpUtils.uriParams(builder.uri()));
+        }
+        return builder;
+    }
+
+    private S3Uri parsePathStyleUri(S3Uri.Builder builder) {
+        String bucket = null;
+        String key = null;
+        String path = builder.uri().getPath();
+
+        if (!StringUtils.isEmpty(path) && !"/".equals(path)) {
+            int index = path.indexOf('/', 1);
+
+            if (index == -1) {
+                // No trailing slash, e.g., "https://s3.amazonaws.com/bucket"
+                bucket = path.substring(1);
+            } else {
+                bucket = path.substring(1, index);
+                if (index != path.length() - 1) {
+                    key = path.substring(index + 1);
+                }
+            }
+        }
+        return builder.key(key)
+                      .bucket(bucket)
+                      .isPathStyle(true)
+                      .build();
+    }
+
+    private S3Uri parseVirtualHostedStyleUri(S3Uri.Builder builder, Matcher matcher) {
+        String bucket;
+        String key = null;
+        String path = builder.uri().getPath();
+        String prefix = matcher.group(1);
+
+        bucket = prefix.substring(0, prefix.length() - 1);
+        if (!StringUtils.isEmpty(path) && !"/".equals(path)) {
+            key = path.substring(1);
+        }
+
+        return builder.key(key)
+                      .bucket(bucket)
+                      .build();
+    }
+
+    private S3Uri parseAwsCliStyleUri(URI uri) {
+        String key = null;
+        String bucket = uri.getAuthority();
+        Region region = null;
+        boolean isPathStyle = false;
+        Map<String, List<String>> queryParams = new HashMap<>();
+        String path = uri.getPath();
+
+        if (bucket == null) {
+            throw new IllegalArgumentException("Invalid S3 URI: bucket not included: " + uri);
+        }
+
+        if (path.length() > 1) {
+            key = path.substring(1);
+        }
+
+        return S3Uri.builder()
+                    .uri(uri)
+                    .bucket(bucket)
+                    .key(key)
+                    .region(region)
+                    .isPathStyle(isPathStyle)
+                    .queryParams(queryParams)
+                    .build();
+    }
+
+    private void validateUri(URI uri) {
+        Validate.paramNotNull(uri, "uri");
+
+        if (uri.toString().contains(".s3-accesspoint")) {
+            throw new IllegalArgumentException("AccessPoints URI parsing is not supported: " + uri);
+        }
+
+        if (uri.toString().contains(".s3-outposts")) {
+            throw new IllegalArgumentException("Outposts URI parsing is not supported: " + uri);
+        }
+    }
+
     private Region resolveRegionForGetUrl(GetUrlRequest getUrlRequest) {
         if (getUrlRequest.region() == null && this.region == null) {
             throw new IllegalArgumentException("Region should be provided either in GetUrlRequest object or S3Utilities object");