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Java Concurrency Uncovered — Part 5: ExecutorService and Thread Pools
A practical guide to using ExecutorService, choosing the right thread pool, and building scalable concurrent applications in Java.
In the previous articles, we explored how Java creates, manages, and synchronizes threads to build safe concurrent applications. As applications grow and need to handle hundreds or thousands of concurrent tasks, manually creating and managing threads becomes increasingly difficult.
Java 5 introduced the Executor Framework to solve this — decoupling what work needs to be done from how and when the threads that execute it are created, reused, and managed. In this article, we’ll explore how to use ExecutorService, choose the right thread pool, and design scalable, production-ready thread pools for real-world applications.
Why Do We Need Thread Pools?
Creating a new thread for every task is simple, but it doesn’t scale well. Each thread consumes memory, and repeatedly creating and destroying threads adds overhead as the number of concurrent tasks grows.
A thread pool addresses these challenges by:
- Reusing worker threads instead of creating a new thread for every task.
