Add UC utils and kernel-spark UC dependency

Author: TimothyW553

build.sbt

@@ -462,6 +462,7 @@ lazy val sparkV1Filtered = (project in file("spark-v1-filtered"))
 lazy val sparkV2 = (project in file("kernel-spark"))
   .dependsOn(sparkV1Filtered)
   .dependsOn(kernelDefaults)
+  .dependsOn(kernelUnityCatalog % "compile->compile;test->test")
   .dependsOn(goldenTables % "test")
   .settings(
     name := "delta-spark-v2",

kernel-spark/src/main/java/io/delta/kernel/spark/snapshot/unitycatalog/SparkUnityCatalogUtils.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright (2025) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.delta.kernel.spark.snapshot.unitycatalog;
+
+import static java.util.Objects.requireNonNull;
+
+import io.delta.kernel.spark.utils.CatalogTableUtils;
+import io.delta.storage.commit.uccommitcoordinator.UCCommitCoordinatorClient;
+import java.util.Map;
+import java.util.Optional;
+import org.apache.spark.sql.SparkSession;
+import org.apache.spark.sql.catalyst.catalog.CatalogTable;
+import org.apache.spark.sql.delta.coordinatedcommits.UCCommitCoordinatorBuilder$;
+
+/**
+ * Utility class for extracting Unity Catalog connection information from Spark catalog metadata.
+ *
+ * <p>This class isolates Spark dependencies, allowing {@link UnityCatalogAdapter} to be created
+ * without Spark if connection info is provided directly via {@link UnityCatalogConnectionInfo}.
+ */
+public final class SparkUnityCatalogUtils {
+
+  // Utility class - no instances
+  private SparkUnityCatalogUtils() {}
+
+  /**
+   * Extracts Unity Catalog connection information from Spark catalog table metadata.
+   *
+   * @param catalogTable Spark catalog table metadata
+   * @param spark SparkSession for resolving Unity Catalog configurations
+   * @return connection info if table is UC-managed, empty otherwise
+   * @throws IllegalArgumentException if table is UC-managed but configuration is invalid
+   */
+  public static Optional<UnityCatalogConnectionInfo> extractConnectionInfo(
+      CatalogTable catalogTable, SparkSession spark) {
+    requireNonNull(catalogTable, "catalogTable is null");
+    requireNonNull(spark, "spark is null");
+
+    if (!CatalogTableUtils.isUnityCatalogManagedTable(catalogTable)) {
+      return Optional.empty();
+    }
+
+    String tableId = extractUCTableId(catalogTable);
+    String tablePath = extractTablePath(catalogTable);
+
+    // Get catalog name
+    scala.Option<String> catalogOption = catalogTable.identifier().catalog();
+    String catalogName =
+        catalogOption.isDefined()
+            ? catalogOption.get()
+            : spark.sessionState().catalogManager().currentCatalog().name();
+
+    // Get UC endpoint and token from Spark configs
+    scala.collection.immutable.List<scala.Tuple3<String, String, String>> scalaConfigs =
+        UCCommitCoordinatorBuilder$.MODULE$.getCatalogConfigs(spark);
+
+    Optional<scala.Tuple3<String, String, String>> configTuple =
+        scala.jdk.javaapi.CollectionConverters.asJava(scalaConfigs).stream()
+            .filter(tuple -> tuple._1().equals(catalogName))
+            .findFirst();
+
+    if (!configTuple.isPresent()) {
+      throw new IllegalArgumentException(
+          "Cannot create UC client: Unity Catalog configuration not found for catalog '"
+              + catalogName
+              + "'.");
+    }
+
+    scala.Tuple3<String, String, String> config = configTuple.get();
+    String endpoint = config._2();
+    String token = config._3();
+
+    return Optional.of(new UnityCatalogConnectionInfo(tableId, tablePath, endpoint, token));
+  }
+
+  private static String extractUCTableId(CatalogTable catalogTable) {
+    Map<String, String> storageProperties =
+        scala.jdk.javaapi.CollectionConverters.asJava(catalogTable.storage().properties());
+
+    String ucTableId = storageProperties.get(UCCommitCoordinatorClient.UC_TABLE_ID_KEY);
+    if (ucTableId == null || ucTableId.isEmpty()) {
+      throw new IllegalArgumentException(
+          "Cannot extract ucTableId from table " + catalogTable.identifier());
+    }
+    return ucTableId;
+  }
+
+  private static String extractTablePath(CatalogTable catalogTable) {
+    if (catalogTable.location() == null) {
+      throw new IllegalArgumentException(
+          "Cannot extract table path: location is null for table " + catalogTable.identifier());
+    }
+    return catalogTable.location().toString();
+  }
+}

kernel-spark/src/main/java/io/delta/kernel/spark/snapshot/unitycatalog/UnityCatalogConnectionInfo.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (2025) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.delta.kernel.spark.snapshot.unitycatalog;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Connection information for Unity Catalog managed tables.
+ *
+ * <p>This POJO encapsulates all the information needed to connect to a Unity Catalog table without
+ * requiring Spark dependencies.
+ */
+public final class UnityCatalogConnectionInfo {
+  private final String tableId;
+  private final String tablePath;
+  private final String endpoint;
+  private final String token;
+
+  public UnityCatalogConnectionInfo(
+      String tableId, String tablePath, String endpoint, String token) {
+    this.tableId = requireNonNull(tableId, "tableId is null");
+    this.tablePath = requireNonNull(tablePath, "tablePath is null");
+    this.endpoint = requireNonNull(endpoint, "endpoint is null");
+    this.token = requireNonNull(token, "token is null");
+  }
+
+  public String getTableId() {
+    return tableId;
+  }
+
+  public String getTablePath() {
+    return tablePath;
+  }
+
+  public String getEndpoint() {
+    return endpoint;
+  }
+
+  public String getToken() {
+    return token;
+  }
+}