Скачать или смотреть How to Effectively Use Data Queueing with Executor Service in Java

Learn how to manage multiple threads efficiently in Java using executor service and data queueing techniques to process a list of data.
---
This video is based on the question https://stackoverflow.com/q/62770787/ asked by the user 'par123' ( https://stackoverflow.com/u/4753860/ ) and on the answer https://stackoverflow.com/a/62771080/ provided by the user 'Ayyoub' ( https://stackoverflow.com/u/9513756/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to use data queueing with executor Service

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Data Queueing with Executor Service in Java

When working with multithreading in Java, one common problem arises: how to coordinate multiple threads while ensuring that they can access and process shared data seamlessly. This becomes particularly important when you need to manage a list of data that various threads should process concurrently, but without any thread processing the same data twice. In this guide, we’ll explore how the Executor Service can be utilized to achieve effective data queueing in a Java application.

The Problem

You may come across a situation where you want to utilize the Executor Service for running tasks in parallel while processing items from a shared list. Each thread should work on a different element from the list. Additionally, it's vital to ensure that each element gets processed only once. The setup is as follows:

You have a pool of threads, managed by Executor Service.

A list of data that these threads will process.

A runnable method that handles the processing of each data item.

Setting Up the Executor Service

Before diving into the solution, let’s establish a basic structure. The ExecutorService provides a high-level API for managing a pool of threads and scheduling tasks. Here’s a simple example of how to set up an ExecutorService:

[[See Video to Reveal this Text or Code Snippet]]

In this line, threadCount is the number of threads you want to run concurrently.

The Solution: Using Data Queueing

To ensure each thread processes elements from the list without duplicating efforts, you can take the following approach using a loop to submit tasks to the executor:

1. Iterate Over Each Element in the List

Instead of having a single runnable task, you'll create individual tasks for each element of your list that needs processing.

2. Submit Tasks to the Executor

Utilise the submit method to send each task to the executor service. Below is a practical implementation of this approach:

[[See Video to Reveal this Text or Code Snippet]]

In the code snippet above:

list.forEach: This lambda expression iterates through every element in the list.

executor.submit(() -> process(e));: For each element, it submits a new task to the executor that invokes the process method on that particular element.

3. Ensure Proper Shutdown of the Executor

After submitting all tasks, it's essential to properly shut down the executor service to avoid leaving threads hanging. You can accomplish this with:

[[See Video to Reveal this Text or Code Snippet]]

Or, if you require all tasks to be completed first, use:

[[See Video to Reveal this Text or Code Snippet]]

Putting It All Together

Here’s the full example of how everything fits together:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Utilizing the Executor Service in Java provides a robust way to manage multithreading effectively, especially when dealing with shared data. By employing the data queueing technique shown above, you can ensure that all elements in your list are processed efficiently and without duplication. With proper management of your threads, you can maximize the performance of your application while maintaining clarity and simplicity in your code.

Feel free to explore more on Java's concurrency features and enhance your multithreading skills!