Java Thread interrupt()

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

In this guide, you will learn about the Thread interrupt() method in Java programming and how to use it with an example.

1. Thread interrupt() Method Overview

Definition:

The Thread.interrupt() method is used to interrupt a thread's execution. If the target thread is currently in a blocking operation (like Thread.sleep(), wait(), or I/O operations), it will receive an InterruptedException.

Syntax:

public void interrupt()

Parameters:

- None.

Key Points:

- Interrupting a thread doesn't necessarily stop its execution but merely sets its interrupt status.

- If a thread is in a blocking operation that supports interruption, it will throw InterruptedException.

- If a thread is not in a blocking state, calling interrupt() will just set the interrupt status, which can be later checked using the Thread.isInterrupted() method.

- It provides a gentle way to tell a thread to stop what it's doing and check if it should terminate (as opposed to forcefully stopping a thread).

2. Thread interrupt() Method Example

public class ThreadInterruptExample {
    public static void main(String[] args) {
        Thread sleepingThread = new Thread(() -> {
            try {
                // This thread will sleep for 10 seconds
                System.out.println("Going to sleep...");
                Thread.sleep(10000);
                System.out.println("Woke up normally.");
            } catch (InterruptedException e) {
                System.out.println("Thread was interrupted during sleep.");
            }
        });

        sleepingThread.start();

        // Give the thread a moment to start sleeping
        try {
            Thread.sleep(2000);
        } catch (InterruptedException ignored) {}

        // Now, interrupt the sleeping thread
        sleepingThread.interrupt();
    }
}

Output:

Going to sleep...
Thread was interrupted during sleep.

Explanation:

In the given example, we create a sleepingThread that tries to sleep for 10 seconds. 

After giving it 2 seconds to start sleeping, we interrupt the sleepingThread. 

Since sleep() is a blocking method that supports interruption, it throws an InterruptedException as soon as the interrupt() method is called on the thread. This is why the output shows "Thread was interrupted during sleep." rather than "Woke up normally.".

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF