Java Guide

cmake -B build -DDDSTREAM_BUILD_JAVA=ON -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(nproc)

export LD_LIBRARY_PATH="$(pwd)/build/source/bindings/java:$LD_LIBRARY_PATH"

# Compile and run
javac -cp build/source/bindings/java/ddstream.jar MyApp.java
java  -cp ".:build/source/bindings/java/ddstream.jar" \
      -Djava.library.path=build/source/bindings/java \
      MyApp

import com.ddstream.*;
import java.time.Instant;

long now = Instant.now().getEpochSecond();

DDStreamConfig cfg = new DDStreamConfig.Builder()
    .apiKey("YOUR_DD_API_KEY")
    .appKey("YOUR_DD_APP_KEY")
    .query("avg:system.cpu.user{*}")
    .rangeStart(now - 86400)   // last 24 hours
    .rangeEnd(now)
    .granularity(60)
    .chunkSeconds(14400)
    .enablePrefetch(true)
    .logLevel(0)
    .build();

// Validate credentials without streaming
String err = DDStream.validate(cfg);
if (err != null) {
    throw new RuntimeException("Invalid credentials: " + err);
}

try (DDStream stream = new DDStream(cfg)) {
    // Range-for (simplest)
    for (DDStream.Batch batch : stream) {
        System.out.printf("Batch: %d points%n", batch.timestamps.length);
    }
}

// Explicit pull with error checking
try (DDStream stream = new DDStream(cfg)) {
    stream.reset();
    while (stream.hasNext()) {
        DDStream.Batch batch = stream.nextBatch();
        if (batch == null) {
            System.err.println("Error: " + stream.lastError());
            break;
        }
        System.out.printf("Progress: %.0f%%%n", stream.progress() * 100);
    }
}

DDStream.Batch batch = stream.nextBatch();

long[]   timestamps = batch.timestamps;  // Unix epoch seconds
double[] avg        = batch.avg;
double[] min        = batch.min;
double[] max        = batch.max;
double[] sum        = batch.sum;

// Chunk metadata
long  startMs = batch.chunkStartMs;
long  endMs   = batch.chunkEndMs;
boolean isLast = batch.isLast;

// Compute stats
double total = 0;
for (double v : avg) total += v;
System.out.printf("Mean CPU: %.2f%%%n", total / avg.length);

// BatchStats
DDStream.BatchStats stats = stream.lastBatchStats();
System.out.printf("Batch #%d, %d points, %d retries%n",
    stats.batchNumber, stats.pointsCount, stats.httpRetries);