feat: use rest namespace for lancedb java sdk (#2845)

After the refactoring on both client and server side, we should have the
ability to fully use lance REST namespace to call into LanceDB cloud and
enterprise. We can avoid having a JNI implementation (which today does
not really do anything except for vending a connection object), and just
use lance-core's RestNamespace.

We will at this moment have a LanceDbRestNamespaceBuilder to allow users
to more easily build the RestNamespace to talk to LanceDB Cloud or
Enterprise endpoint.

In the future, we could extend this further to also support the local
mode through DirectoryNamespace. That will be a separated PR.

java/lancedb-core/src/test/java/com/lancedb/LanceDbRestNamespaceBuilderTest.java

@@ -0,0 +1,96 @@
+/*
+ * 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;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/** Unit tests for LanceDbRestNamespaceBuilder. */
+public class LanceDbRestNamespaceBuilderTest {
+
+  @Test
+  public void testBuilderRequiresApiKey() {
+    LanceDbRestNamespaceBuilder builder =
+        LanceDbRestNamespaceBuilder.newBuilder().database("test-db");
+
+    IllegalStateException exception = assertThrows(IllegalStateException.class, builder::build);
+    assertEquals("API key is required", exception.getMessage());
+  }
+
+  @Test
+  public void testBuilderRequiresDatabase() {
+    LanceDbRestNamespaceBuilder builder =
+        LanceDbRestNamespaceBuilder.newBuilder().apiKey("test-api-key");
+
+    IllegalStateException exception = assertThrows(IllegalStateException.class, builder::build);
+    assertEquals("Database is required", exception.getMessage());
+  }
+
+  @Test
+  public void testApiKeyCannotBeNull() {
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> LanceDbRestNamespaceBuilder.newBuilder().apiKey(null));
+    assertEquals("API key cannot be null or empty", exception.getMessage());
+  }
+
+  @Test
+  public void testApiKeyCannotBeEmpty() {
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> LanceDbRestNamespaceBuilder.newBuilder().apiKey("  "));
+    assertEquals("API key cannot be null or empty", exception.getMessage());
+  }
+
+  @Test
+  public void testDatabaseCannotBeNull() {
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> LanceDbRestNamespaceBuilder.newBuilder().database(null));
+    assertEquals("Database cannot be null or empty", exception.getMessage());
+  }
+
+  @Test
+  public void testDatabaseCannotBeEmpty() {
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> LanceDbRestNamespaceBuilder.newBuilder().database("  "));
+    assertEquals("Database cannot be null or empty", exception.getMessage());
+  }
+
+  @Test
+  public void testBuilderFluentApi() {
+    // Verify the builder returns itself for chaining
+    LanceDbRestNamespaceBuilder builder = LanceDbRestNamespaceBuilder.newBuilder();
+
+    assertSame(builder, builder.apiKey("test-key"));
+    assertSame(builder, builder.database("test-db"));
+    assertSame(builder, builder.endpoint("http://localhost:8080"));
+    assertSame(builder, builder.region("eu-west-1"));
+    assertSame(builder, builder.config("custom-key", "custom-value"));
+  }
+
+  @Test
+  public void testNewBuilderCreatesNewInstance() {
+    LanceDbRestNamespaceBuilder builder1 = LanceDbRestNamespaceBuilder.newBuilder();
+    LanceDbRestNamespaceBuilder builder2 = LanceDbRestNamespaceBuilder.newBuilder();
+
+    assertNotSame(builder1, builder2);
+  }
+}

java/lancedb-core/src/test/resources/log4j2.xml

@@ -0,0 +1,32 @@
+<?xml version='1.0' encoding='UTF-8'?>
+
+<!--
+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.
+-->
+
+<configuration monitorInterval="30">
+    <appenders>
+        <Console name='Console' target='SYSTEM_ERR'>
+            <PatternLayout pattern='%d{HH:mm:ss.SSS} %p [%t] %C{1}.%M: %m%n'/>
+        </Console>
+    </appenders>
+    <loggers>
+        <logger name='com.lancedb' level='DEBUG' additivity='false'>
+            <appender-ref ref='Console'/>
+        </logger>
+        <root level='INFO'>
+            <appender-ref ref='Console'/>
+        </root>
+    </loggers>
+</configuration>