feat: add Polaris Catalog namespace implementation

docs/src/impls/polaris.md

@@ -0,0 +1,54 @@
+# Lance Polaris Namespace
+
+**Lance Polaris Namespace** is an implementation using Polaris Catalog's Generic Table API.
+The Polaris namespace uses the following API endpoints:
+- **Namespace operations**: Standard Iceberg REST API endpoints (`/namespaces`)
+- **Table operations**: Generic Table API endpoints (`/namespaces/{namespace}/generic-tables`)
+
+For more details about Polaris Catalog, please read the [Polaris Catalog Documentation](https://github.com/polaris-catalog/polaris).
+
+## Configuration
+
+The Lance Polaris namespace accepts the following configuration properties:
+
+| Property          | Required | Description                                    | Default | Example                    |
+|-------------------|----------|------------------------------------------------|---------|----------------------------|
+| `endpoint`        | Yes      | Polaris server endpoint URL                   |         | `http://localhost:8182`    |
+| `auth_token`      | No       | Bearer token for authentication               |         | `your-auth-token`          |
+| `connect_timeout` | No       | Connection timeout in milliseconds            | 10000   | `30000`                    |
+| `read_timeout`    | No       | Read timeout in milliseconds                  | 30000   | `60000`                    |
+| `max_retries`     | No       | Maximum number of retries for failed requests | 3       | `5`                        |
+
+### Authentication
+
+The Polaris namespace supports bearer token authentication:
+
+1. **Bearer Token**: Set `auth_token` with a valid Polaris access token
+2. **No Authentication**: For local or unsecured Polaris deployments
+
+## Namespace Mapping
+
+Polaris provides a flexible namespace hierarchy:
+
+- A catalog in Polaris maps to the first level Lance namespace
+- Nested namespaces in Polaris map to subsequent Lance namespace levels
+- Polaris supports arbitrary nesting depth, allowing flexible namespace organization
+
+## Table Definition
+
+A Lance table appears as a [Generic Table](https://github.com/polaris-catalog/polaris/blob/main/spec/polaris-catalog-apis/generic-tables-api.yaml)
+object in Polaris with the following requirements:
+
+1. the `format` must be set to `lance` to indicate this is a Lance table
+2. the `base-location` must point to the root location of the Lance table
+3. the `doc` field can be used to store an optional table description
+4. the `properties` must follow:
+   1. there is a key `table_type` set to `lance` (case insensitive)
+   2. there is a key `managed_by` set to either `storage` or `impl` (case insensitive). If not set, default to `storage`
+   3. there is a key `version` set to the latest numeric version number of the table. This field will only be respected if `managed_by=impl`
+
+## Requirement for Implementation Managed Table
+
+Updates to implementation-managed Lance tables must use Polaris's table versioning mechanism
+for conditional updates through the UpdateTable API. The `version` property must be updated atomically
+to prevent concurrent modification conflicts.

java/lance-namespace-polaris/pom.xml

@@ -0,0 +1,83 @@
+<?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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>com.lancedb</groupId>
+    <artifactId>lance-namespace-root</artifactId>
+    <version>0.0.7</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+
+  <artifactId>lance-namespace-polaris</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Lance Namespace Polaris</name>
+  <description>Polaris Catalog implementation for Lance namespace management</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.lancedb</groupId>
+      <artifactId>lance-namespace-core</artifactId>
+      <version>${lance-namespace.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-annotations</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jsr310</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+
+    <!-- Test dependencies -->
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.assertj</groupId>
+      <artifactId>assertj-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>ch.qos.logback</groupId>
+      <artifactId>logback-classic</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>