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wickra/bindings/wasm/README.md
T
kingchencandGitHub 167f7b3ffe Add the Java binding over the C ABI hub (Panama/FFM) (#233)
Adds a Java binding (`bindings/java`) over the C ABI hub — the fourth language stecker after C#, Go and R, reaching the hub through the Java Foreign Function & Memory API (Panama, `java.lang.foreign`, final in Java 22) rather than JNI or jextract.

## What's here
- **`bindings/java`** — a Maven module (`org.wickra:wickra`) exposing all 514 indicators as idiomatic `AutoCloseable` classes. The downcall handles (`internal/NativeMethods.java`), the per-indicator wrappers and the output records are generated from `bindings/c/include/wickra.h` (same eight-archetype taxonomy as the C#/Go/R generators: scalar/batch, multi-output, bars, profile, values-profile, array-input). The opaque handle is a `MemorySegment` freed by a registered `java.lang.ref.Cleaner` action; multi-output returns a `record` (`null` at warmup), bars a `record[]`, profiles a record with a trailing `double[]`. The hand-written `WickraNative` resolves the native library (a bundled per-platform copy, or a `target/release` fallback for local development) and validates it against a sentinel symbol. repr(C) struct offsets are computed in the generator so the FFM reads land on the exact bytes.
- **`examples/java`** — the full example suite mirroring C/C#/Go/R: streaming, backtest, multi_timeframe, parallel_assets (parallel streams), three strategies, and `FetchBtcusdt`/`LiveBinance`.
- **CI** — a `java` job builds the C ABI library, sets up JDK 22 (Temurin, with a CDN-flake retry), runs the archetype test suite and the seven offline examples on Linux, macOS and Windows.
- **Release** — a gated `java-publish` job (skipped until the `JAVA_PUBLISH_ENABLED` repository variable is set) stages the native libraries from the `wickra-c-<triple>.tar.gz` assets into the binding's resources and deploys to Maven Central with GPG signing. Independent of the GitHub-release job, like the NuGet job.
- **Docs** — Java added to the README languages table, project layout, building/testing and comparison table, CONTRIBUTING, ARCHITECTURE, the examples index, the issue/PR templates, the About-description template, and the other binding READMEs.

## Requirements
Java 22+ (the FFM API is final since Java 22). The binding requires `--enable-native-access=ALL-UNNAMED` at runtime; the test and example runners pass it automatically.

No Rust crate or `Cargo.toml` change — the Java binding is standalone and additive. The generated `*.java` are committed (like the node `index.js`/`index.d.ts`); the generator stays private.
2026-06-09 20:30:29 +02:00

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# Wickra — WebAssembly
[![CI](https://github.com/wickra-lib/wickra/actions/workflows/ci.yml/badge.svg)](https://github.com/wickra-lib/wickra/actions/workflows/ci.yml)
[![codecov](https://codecov.io/gh/wickra-lib/wickra/branch/main/graph/badge.svg)](https://codecov.io/gh/wickra-lib/wickra)
[![npm](https://img.shields.io/npm/v/wickra-wasm.svg?logo=npm&color=red)](https://www.npmjs.com/package/wickra-wasm)
[![License: MIT OR Apache-2.0](https://img.shields.io/badge/license-MIT_OR_Apache--2.0-blue)](https://github.com/wickra-lib/wickra#license)
**Streaming-first technical indicators in the browser. `npm install
wickra-wasm` — pure WebAssembly, runs anywhere a modern JS engine does.**
Wickra is a multi-language technical-analysis library with a Rust core and
bindings for Python, Node.js and WebAssembly, plus a C ABI for C/C++, C#, Go, Java, R and any
other C-capable language. Every indicator is an O(1)
streaming state machine, so live trading dashboards and historical backtests
share the exact same implementation. This package is the WebAssembly binding
(wasm-bindgen, built for the `web` target); it exposes 200+ streaming-first
indicators across sixteen families.
## Install
```bash
npm install wickra-wasm
```
## Quick start
The module ships a default `init` export that loads the `.wasm` payload; await
it once before constructing indicators.
```js
import init, { RSI } from 'wickra-wasm';
await init(); // load the WebAssembly module once
// Streaming: feed prices tick by tick in O(1).
const rsi = new RSI(14);
for (const price of liveFeed) {
const value = rsi.update(price); // null during warmup
if (value !== null && value > 70) {
console.log('overbought');
}
}
```
Constructors mirror the other bindings (`new SMA(20)`, `new MACD(12, 26, 9)`,
`new BollingerBands(20, 2.0)`, …); `update()` returns the latest value or
`null` while the indicator is still warming up.
## Documentation
The full indicator catalogue, guides, quickstarts, and API reference live in
the main repository and documentation site:
- **Repository & full indicator list:** <https://github.com/wickra-lib/wickra>
- **Docs** (quickstarts, cookbook, TA-Lib migration): <https://docs.wickra.org>
- **Runnable browser examples:** [`examples/wasm/`](https://github.com/wickra-lib/wickra/tree/main/examples/wasm)
Wickra ships native bindings for Python, Node.js, WebAssembly and Rust, plus a
C ABI hub that any C-capable language (C, C++, Go, C#, Java, R) links against —
all exposing the same indicators from the shared, `unsafe`-forbidden Rust core.
## Disclaimer
Wickra is an indicator toolkit, not a trading system. The values it computes
are deterministic transforms of the input data — they are not financial advice
and do not predict the market. Any use in a live trading context is at your own
risk. The library is provided **as is**, without warranty of any kind.
## License
Licensed under either of [Apache-2.0](https://github.com/wickra-lib/wickra/blob/main/LICENSE-APACHE)
or [MIT](https://github.com/wickra-lib/wickra/blob/main/LICENSE-MIT) at your option.