Java Concurrency Tutorial

Java concurrency is a crucial aspect of Java programming that allows for the creation of efficient, scalable, and responsive applications. This tutorial will guide you through the basics of concurrency in Java, including threads, synchronization, and the Executor framework.

What is Concurrency?

Concurrency refers to the ability of a computer to execute multiple tasks at the same time. In Java, concurrency is achieved through the use of threads, which are lightweight processes that run concurrently with the main application thread.

Threads in Java

In Java, a thread is a unit of execution within a process. You can create threads in two ways:

• Extending the Thread class: This is the traditional way of creating threads in Java. You create a subclass of Thread and override the run method, which contains the code to be executed by the thread.

public class MyThread extends Thread {
    @Override
    public void run() {
        // Code to be executed by the thread
    }
}

• Implementing the Runnable interface: This is a more modern approach that allows you to separate the thread logic from the class that implements it.

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        // Code to be executed by the thread
    }
}

Synchronization

When multiple threads access shared resources, it's important to ensure that the access is synchronized to avoid race conditions and other concurrency issues. In Java, you can use synchronized blocks or methods to achieve this.

public class Counter {
    private int count = 0;

    public synchronized void increment() {
        count++;
    }
}

Executor Framework

The Executor framework provides a high-level abstraction for managing and executing asynchronous tasks. It allows you to execute tasks in parallel, submit tasks to a thread pool, and control the execution of tasks.

ExecutorService executor = Executors.newFixedThreadPool(4);
executor.submit(new MyRunnable());
executor.shutdown();

Conclusion

Concurrency in Java is a complex topic, but it's essential for creating efficient and scalable applications. By understanding the basics of threads, synchronization, and the Executor framework, you can leverage the full power of Java's concurrency features.

For more information on Java concurrency, check out our comprehensive guide on Java Concurrency Best Practices.

Concurrency