feat: add hms list namespaces

LICENSE

@@ -199,3 +199,20 @@
    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.
+
+--------------------------------------------------------------------------------
+
+This product includes code from Apache Iceberg. The following files are copied from iceberg, and some of them have been slightly modified.
+
+* DynMethods.java
+* DynConstructors.java
+* Configurable.java
+* ClientPool.java
+* ClientPoolImpl.java
+* HiveClientPool.java
+* RuntimeMetaException.java
+* TestHiveMetastore.java
+
+Copyright: 2004-2025 The Apache Software Foundation.
+Home page: https://iceberg.apache.org/
+License: https://www.apache.org/licenses/LICENSE-2.0

java/checkstyle.xml

@@ -172,10 +172,15 @@
             <property name="illegalPkgs" value="org.apache.log4j" />
             <property name="illegalPkgs" value="org.apache.commons.lang" />
         </module>
-        <!-- support structured logging -->
-        <module name="RegexpSinglelineJava">
-            <property name="format" value="org\.slf4j\.(Logger|LoggerFactory)" />
-            <property name="message" value="Please use org.apache.spark.internal.(SparkLogger|SparkLoggerFactory) instead." />
+        <module name="IllegalImport">
+            <property name="illegalPkgs" value="org.apache.hadoop.hbase.shaded" />
+            <message key="import.illegal"
+                     value="Do not use HBase shaded classes."/>
+        </module>
+        <module name="IllegalImport">
+            <property name="illegalPkgs" value="org.apache.parquet" />
+            <message key="import.illegal"
+                     value="Do not use Parquet classes directly."/>
         </module>
     </module>
 </module>

java/lance-namespace-core/pom.xml

@@ -23,6 +23,11 @@
             <artifactId>lance-namespace-apache-client</artifactId>
             <version>${lance-namespace.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>33.4.0-jre</version>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter</artifactId>

java/lance-namespace-core/src/main/java/com/lancedb/lance/namespace/Configurable.java

@@ -0,0 +1,20 @@
+/*
+ * 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 com.lancedb.lance.namespace;
+
+// Copied from apache iceberg.
+// https://github.com/apache/iceberg/blob/main/core/src/main/java/org/apache/iceberg/hadoop/Configurable.java
+public interface Configurable<C> {
+  void setConf(C conf);
+}

java/lance-namespace-core/src/main/java/com/lancedb/lance/namespace/LanceNamespace.java

@@ -53,9 +53,41 @@
 import com.lancedb.lance.namespace.model.TableExistsResponse;
 import com.lancedb.lance.namespace.model.UpdateTableRequest;
 import com.lancedb.lance.namespace.model.UpdateTableResponse;
+import com.lancedb.lance.namespace.util.DynConstructors;
+
+import java.util.Map;
 
 /** TODO: add documentation */
 public interface LanceNamespace {
+  static LanceNamespace create(String name, Map<String, String> properties, Object conf) {
+    String impl =
+        properties.getOrDefault(NamespaceProperties.NS_IMPL, NamespaceProperties.NS_IMPL_DEFAULT);
+
+    LanceNamespace ns;
+    try {
+      ns =
+          (LanceNamespace)
+              DynConstructors.builder(LanceNamespace.class).impl(impl).buildChecked().newInstance();
+    } catch (NoSuchMethodException e) {
+      throw new IllegalArgumentException(
+          String.format("Failed to construct namespace, impl: %s", impl), e);
+    }
+
+    if (ns instanceof Configurable && conf != null) {
+      ((Configurable) ns).setConf(conf);
+    }
+
+    ns.initialize(name, properties);
+    return ns;
+  }
+
+  /**
+   * Initialize namespace with custom name and conf properties.
+   *
+   * @param name a custom name for the namespace
+   * @param properties namespace conf properties
+   */
+  default void initialize(String name, Map<String, String> properties) {}
 
   ListNamespacesResponse listNamespaces(ListNamespacesRequest request);
 

java/lance-namespace-core/src/main/java/com/lancedb/lance/namespace/NamespaceProperties.java

@@ -0,0 +1,20 @@
+/*
+ * 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 com.lancedb.lance.namespace;
+
+public class NamespaceProperties {
+  public static final String NS_IMPL = "lance.namespace.impl";
+  public static final String NS_IMPL_DEFAULT =
+      "com.lancedb.lance.namespace.hive.LanceHiveNamespace";
+}

java/lance-namespace-core/src/main/java/com/lancedb/lance/namespace/ObjectIdentifier.java

@@ -0,0 +1,60 @@
+/*
+ * 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 com.lancedb.lance.namespace;
+
+import com.lancedb.lance.namespace.util.ValidationUtil;
+
+import com.google.common.collect.ImmutableList;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class ObjectIdentifier {
+  private String[] levels;
+
+  private ObjectIdentifier(String[] levels) {
+    this.levels = levels;
+  }
+
+  public static ObjectIdentifier of(List<String> levels) {
+    levels.stream()
+        .forEach(
+            level ->
+                ValidationUtil.checkNotNullOrEmptyString(
+                    level, "Invalid namespace containing empty string %s", levels));
+    return new ObjectIdentifier(levels.toArray(new String[0]));
+  }
+
+  public String level(int pos) {
+    return levels[pos];
+  }
+
+  public String name() {
+    return empty() ? "" : levels[levels.length - 1];
+  }
+
+  public List<String> parent() {
+    return size() < 2
+        ? ImmutableList.of()
+        : ImmutableList.copyOf(Arrays.copyOfRange(levels, 0, levels.length - 1));
+  }
+
+  public int size() {
+    return levels == null ? 0 : levels.length;
+  }
+
+  public boolean empty() {
+    return size() == 0;
+  }
+}