Batch4j

Simple batch processing library for java.

Installation

Require java 8+.

Add library to gradle dependencies.

dependencies {
    implementation 'io.github.mawngo:batch4j:1.0.0'
}

Usage

Example usage:

import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import io.github.mawngo.batch4j.BatchProcessors;
import io.github.mawngo.batch4j.RunningProcessor;
import io.github.mawngo.batch4j.ParallelProcessor;
import io.github.mawngo.batch4j.handlers.BatchMerger;

@Test
void example() {
    final AtomicInteger sum = new AtomicInteger(0);
    final RunningProcessor<Integer> processor = BatchProcessors
        .newBuilder((List<Integer> list) -> sum.updateAndGet(i -> i + list.size()))
        .maxWait(1000, TimeUnit.MILLISECONDS)       // maximum wait time before processing
        .maxItem(100)                               // maximum item in batch before processing
        .build(BatchMerger.mergeToList())
        .run();
    for (int i = 0; i < 1_000_000; i++) {
        processor.put(i);
    }
    processor.close();
    Assertions.assertEquals(1_000_000, sum.get());
}

@Test
void exampleParallel() {
    final AtomicInteger sum = new AtomicInteger(0);
    final ParallelProcessor<Integer> processor = BatchProcessors
        .newBuilder((List<Integer> list) -> sum.updateAndGet(i -> i + list.size()))
        .maxWait(1000, TimeUnit.MILLISECONDS)
        .maxItem(100)
        .parallelTo(Executors.newCachedThreadPool()) // specify executor for parallel processing
        //.parallel("2-10")                          // or specify parallel for auto creating one.
        .build(BatchMerger.mergeToList())
        .run();
    for (int i = 0; i < 1_000_000; i++) {
        processor.put(i);
    }
    processor.close();
    processor.closeExecutor();                        // optional, closing backing executor.
    Assertions.assertEquals(1_000_000, sum.get());
}