wickra/bindings/java/README.md

Wickra — Java

Streaming-first technical indicators for the JVM, on the Java Foreign Function & Memory API — prebuilt native library, no JNI, no system dependencies.

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 bots and historical backtests share the exact same implementation. This package is the Java binding; it consumes the C ABI hub through the Panama FFM API (java.lang.foreign) and exposes all 514 streaming-first indicators as idiomatic AutoCloseable classes.

Requirements

• Java 22 or later (the FFM API is final since Java 22; no preview flag).
• The FFM API is restricted: pass --enable-native-access=ALL-UNNAMED when you run your application to silence the native-access warning.

Install

Maven:

<dependency>
  <groupId>org.wickra</groupId>
  <artifactId>wickra</artifactId>
  <version>0.8.3</version>
</dependency>

Gradle:

implementation("org.wickra:wickra:0.8.3")

The native library ships prebuilt per platform (Linux, macOS, Windows — x64 and arm64) inside the jar and is extracted automatically on first use. There is nothing to compile.

Quick start

import org.wickra.Ema;
import org.wickra.Rsi;

// Batch: run an indicator over a whole series (NaN at warmup positions).
double[] prices = new double[1000];
for (int i = 0; i < prices.length; i++) {
    prices[i] = 100.0 + i * 0.1;
}
try (Ema ema = new Ema(20)) {
    double[] values = ema.batch(prices);
}

// Streaming: the same indicator, fed tick by tick in O(1).
try (Rsi rsi = new Rsi(14)) {
    for (double price : liveFeed) {
        double value = rsi.update(price); // NaN during warmup, no recomputation
        if (Double.isFinite(value) && value > 70) {
            System.out.println("overbought");
        }
    }
}

batch(prices) and feeding the same prices through update() produce identical values — the equivalence is enforced by the test suite. Multi-output indicators (MACD, Bollinger, ADX, …) return a record, null while warming up. Each indicator owns a native handle freed by a Cleaner; close() releases it eagerly (use try-with-resources).

Benchmark

benchmarks/ reports streaming and batch updates-per-second for SMA, ATR and MACD. It measures this binding's FFI overhead, not a cross-library ratio (the same Rust core runs under every binding) — see the repository BENCHMARKS.md §3.

cargo build -p wickra-c --release
mvn -q install -DskipTests
mvn -q -f benchmarks exec:exec -Dexec.mainClass=org.wickra.benchmarks.Throughput

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 examples: examples/java/

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 or MIT at your option.