docs: add javadoc to docs.vortex.dev (#4229)

I've verified this locally with `make serve`

Signed-off-by: Andrew Duffy <[email protected]>

Author: a10y

.github/workflows/docs.yml

@@ -18,10 +18,25 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - uses: ./.github/actions/setup-rust
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: "17"
+          distribution: "temurin"
       - name: Install uv
         uses: spiraldb/actions/.github/actions/[email protected]
         with:
           sync: false
+      - name: Generate Javadoc for Java projects
+        run: |
+          cd java
+          ./gradlew javadoc -x makeTestFiles -x shadowJar
+      - name: Copy Javadoc to docs directory
+        run: |
+          mkdir -p docs/_static/vortex-jni
+          mkdir -p docs/_static/vortex-spark
+          cp -r java/vortex-jni/build/docs/javadoc/* docs/_static/vortex-jni/
+          cp -r java/vortex-spark/build/docs/javadoc/* docs/_static/vortex-spark/
       - name: build Python and Rust docs
         run: |
           uv run --all-packages make -C docs html

docs/_static/.gitignore

@@ -0,0 +1,2 @@
+vortex-spark/
+vortex-jni/

docs/api/java/index.rst

@@ -0,0 +1,43 @@
+Vortex Java API
+===============
+
+The Vortex Java API provides bindings for the Vortex library, enabling Java applications to work with Vortex arrays and files.
+
+The API is split into two main components:
+
+* **Vortex JNI**: Core JNI bindings for Vortex functionality
+* **Vortex Spark**: Apache Spark integration for reading Vortex files
+
+.. raw:: html
+
+   <div class="api-links">
+   <h3>API Documentation</h3>
+   <ul>
+     <li><a href="../../_static/vortex-jni/index.html">Vortex JNI API</a> - Core Java bindings for Vortex</li>
+     <li><a href="../../_static/vortex-spark/index.html">Vortex Spark API</a> - Apache Spark integration</li>
+   </ul>
+   </div>
+
+Installation
+------------
+
+The Java API can be included in your project using Gradle or Maven. Please refer to the main documentation for detailed installation instructions.
+
+Usage Example
+-------------
+
+Here's a basic example of using the Vortex Java API to read a Vortex file:
+
+.. code-block:: java
+
+    import dev.vortex.api.File;
+    import dev.vortex.api.Array;
+    
+    // Open a Vortex file
+    File vortexFile = File.open("path/to/file.vortex");
+    
+    // Read arrays from the file
+    Array array = vortexFile.readArray();
+    
+    // Work with the array data
+    System.out.println("Array length: " + array.getLength());

docs/index.md

@@ -96,6 +96,7 @@ caption: API Documentation
 Python API <api/python/index>
 Rust API <https://docs.rs/vortex>
 C FFI API <api/c/index>
+Java API <api/java/index>
 ```
 
 ## User Guides