jons-mcp-java

# jons-mcp-java MCP server that provides Java language intelligence through Eclipse JDT.LS. Released packages are available from PyPI. Development versions can also be run from a source checkout or directly from GitHub. The current public API is aligned with `jons-mcp-typescript`: public positions are one-based, successful tool responses use structured `items` and pagination shapes, and refactoring previews are read-only. ## Requirements - Python 3.10+ - Java 21+ - Eclipse JDT.LS - A target Java workspace containing Gradle project markers: `settings.gradle`, `settings.gradle.kts`, `build.gradle`, or `build.gradle.kts` On macOS with Homebrew: ```bash brew install openjdk@21 jdtls ``` If Java is not on your PATH, set `JAVA_HOME`. If JDT.LS is installed somewhere custom, set `JDTLS_HOME`. The server also tries to resolve a `jdtls` executable on PATH. If `JDTLS_HOME` points at a read-only install such as the Nix store, the server copies the small platform `config_<os>` directory into a writable cache under `$XDG_CACHE_HOME/jons-mcp-java` or `~/.cache/jons-mcp-java`. Set `JDTLS_CONFIG_DIR` to choose a specific writable configuration directory. The cached copy is repaired to be user-writable even when the source archive or package ships read-only mode bits. ## Install and Run From PyPI: ```bash uvx jons-mcp-java /path/to/java-workspace ``` From a source checkout: ```bash git clone [email protected]:jonmmease/jons-mcp-java.git cd jons-mcp-java uv sync uv run jons-mcp-java /path/to/java-workspace ``` From GitHub without a persistent checkout: ```bash uvx --from git+https://github.com/jonmmease/jons-mcp-java.git \ jons-mcp-java /path/to/java-workspace ``` Pass the Java workspace root as the optional positional argument, or set `JONS_MCP_JAVA_WORKSPACE`. The positional argument takes precedence. If neither is provided, the server uses the MCP process current working directory. All relative tool paths are resolved from this workspace root. ## MCP Client Exa…