Stream.parallel (): Start the journey of parallel stream processing

Java 8 introduces the powerful Stream API, which provides a concise and efficient solution for processing collection data. Among them, the parallel ()method introduces parallelization capability for stream processing, allowing developers to fully utilize the advantages of multi-core processors and greatly improve the processing efficiency of large-scale datasets.

This article will take you on a journey of parallel stream processing and introduce you to the parallel ()in the Java 8 Stream API.

What is parallel ()

Parallel ()is a method in the Java 8 Stream API used to convert a sequential stream into a parallel stream. A parallel stream is a stream that can perform operations on multiple threads simultaneously. It divides the elements of the stream into multiple subsets, each of which is processed independently on different threads, and finally merges the results. Using the parallel ()method can easily enable parallel stream processing mode without explicitly managing threads and synchronization.

List<Integer> numbers = ...; // 假设有一个包含大量元素的列表numbers.stream() // 创建顺序流
    .parallel() // 转换为并行流
    .filter(n -> n % 2 == 0) // 并行过滤偶数
    .map(n -> n * 2) // 并行映射为原数的两倍
    .forEach(System.out::println); // 并行打印结果

In this example, the parallel ()method converts the sequential stream to a parallel stream, and subsequent filter (), map ()and forEach ()operations are executed in parallel on…