address Copilot comments

Author: sfc-gh-dszmolka

src/main/java/net/snowflake/client/internal/jdbc/cloud/storage/SnowflakeS3Client.java

@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Base64;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Properties;
 import java.util.concurrent.CompletableFuture;
@@ -174,7 +175,15 @@ private void setupSnowflakeS3Client(
     if (this.stageEndPoint != null
         && !this.stageEndPoint.isEmpty()
         && !"null".equals(this.stageEndPoint)) {
-      clientBuilder.endpointOverride(resolveStageEndpointUriForOverride(this.stageEndPoint));
+      String endpointForOverride = this.stageEndPoint;
+      String lower = endpointForOverride.toLowerCase(Locale.ROOT);
+      if (!lower.startsWith("https://") && !lower.startsWith("http://")) {
+        logger.debug(
+            "AWS S3 Client: stage endpoint {} has no scheme, normalizing for URI creation.",
+            this.stageEndPoint);
+        endpointForOverride = "https://" + endpointForOverride;
+      }
+      clientBuilder.endpointOverride(URI.create(endpointForOverride));
       clientBuilder.region(region);
     } else {
       if (this.isUseS3RegionalUrl) {
@@ -233,38 +242,6 @@ private void setupSnowflakeS3Client(
     amazonClient = clientBuilder.build();
   }
 
-  /**
-   * Builds a {@link URI} for {@code endpointOverride} with a non-null scheme (required by AWS SDK
-   * v2). Uses {@link URI#getScheme()} and compares {@code http}/{@code https} case-insensitively
-   * per RFC 3986; bare hostnames get an {@code https://} prefix.
-   *
-   * <p>{@link URI#create(String)} only throws {@link IllegalArgumentException}, wrapping {@link
-   * java.net.URISyntaxException} when the string violates RFC&nbsp;2396 / RFC&nbsp;3986.
-   */
-  private URI resolveStageEndpointUriForOverride(String raw) {
-    URI parsed;
-    try {
-      parsed = URI.create(raw);
-    } catch (IllegalArgumentException ex) {
-      logger.debug(
-          "AWS S3 Client: could not parse stage endpoint as URI; raw=\""
-              + raw
-              + "\"; prefixing https://",
-          ex);
-      return URI.create("https://" + raw);
-    }
-    String scheme = parsed.getScheme();
-    if (scheme == null || scheme.isEmpty()) {
-      logger.debug(
-          "AWS S3 Client: stage endpoint {} has no scheme, normalizing for URI creation.", raw);
-      return URI.create("https://" + raw);
-    }
-    if (scheme.equalsIgnoreCase("https") || scheme.equalsIgnoreCase("http")) {
-      return parsed;
-    }
-    return parsed;
-  }
-
   static String getDomainSuffixForRegionalUrl(String regionName) {
     return regionName.toLowerCase().startsWith("cn-") ? "amazonaws.com.cn" : "amazonaws.com";
   }

src/test/java/net/snowflake/client/internal/jdbc/cloud/storage/SnowflakeS3ClientTest.java

@@ -41,10 +41,7 @@ public void shouldDocumentBareAwsHostnameHasNullUriScheme() {
   public void shouldPrependHttpsWhenStageEndpointHasNoScheme() throws Exception {
     SnowflakeS3Client client =
         newClient(
-            "eu-west-1",
-            "s3.eu-west-1.amazonaws.com",
-            false,
-            /* isClientSideEncrypted */ false);
+            "eu-west-1", "s3.eu-west-1.amazonaws.com", false, /* isClientSideEncrypted */ false);
     try {
       URI override = endpointOverride(client).get();
       assertEquals("https", override.getScheme());
@@ -154,10 +151,7 @@ public void shouldBuildClientWithoutNpeWhenStageEndpointIsSchemelessHost() throw
     try {
       client =
           newClient(
-              "us-west-2",
-              "s3.us-west-2.amazonaws.com",
-              false,
-              /* isClientSideEncrypted */ false);
+              "us-west-2", "s3.us-west-2.amazonaws.com", false, /* isClientSideEncrypted */ false);
       assertNotNull(client);
       assertTrue(endpointOverride(client).isPresent());
       assertNotNull(endpointOverride(client).get().getScheme());