Java

Verified against the Rust reference. Every one of Wickra's 514 indicators is replayed through all 10 languages and checked bit-for-bit against the Rust core's golden fixtures in CI — the math here is provably identical to every other binding (how).

The Java binding is a language shim on the C ABI hub built on the Java Foreign Function & Memory API (Panama). It ships on Maven Central as org.wickra:wickra with the native library prebuilt for every supported platform; there is nothing to compile.

<dependency>
  <groupId>org.wickra</groupId>
  <artifactId>wickra</artifactId>
  <version>0.9.9</version>
</dependency>

• Distribution: Maven Central (org.wickra:wickra), native libraries bundled per platform (win/linux/osx × x64/arm64).
• Requirements: Java 22+ (the FFM API is final since Java 22). Run with --enable-native-access=ALL-UNNAMED.
• Built on: the C ABI hub via the Java FFM API (java.lang.foreign), generated from wickra.h — not JNI, not jextract.
• Memory model: opaque handles are MemorySegments freed by a java.lang.ref.Cleaner; try-with-resources for deterministic cleanup.

The class shape

Every indicator is an AutoCloseable class with update / batch / warmupPeriod / isReady / reset. Prefer try-with-resources so the native handle is freed deterministically.

import org.wickra.Sma;

try (Sma sma = new Sma(14)) {      // throws IllegalArgumentException on invalid params
    int w = sma.warmupPeriod();    // updates until ready: 14
    double v = sma.update(42.0);   // NaN while warming up
    boolean ready = sma.isReady(); // false until warmed up
    sma.reset();
} // freed at the end of the try-with-resources scope

The alt-chart bar builders (RenkoBars, KagiBars, …) have no warmupPeriod / isReady — a candle can complete 0..n bars, so they have no warmup.

Streaming

try (Rsi rsi = new Rsi(14)) {
    for (double price : feed) {
        double v = rsi.update(price);
        if (Double.isFinite(v) && v > 70.0) {
            System.out.printf("overbought %.2f%n", v);
        }
    }
}

Batch (one call over a whole series)

try (Ema ema = new Ema(20)) {
    double[] values = ema.batch(prices); // NaN at warmup positions
}

Multi-output indicators

Indicators with several outputs return a record — null while warming up:

try (MacdIndicator macd = new MacdIndicator(12, 26, 9)) {
    for (double price : feed) {
        MacdOutput m = macd.update(price);
        if (m != null) {
            System.out.printf("macd=%.4f signal=%.4f hist=%.4f%n",
                m.macd(), m.signal(), m.histogram());
        }
    }
}

Candle-input indicators take OHLCV plus a timestamp, e.g. atr.update(open, high, low, close, volume, timestamp).

More

• Quickstart: Java (docs)
• Examples
• Benchmarks