How to Handle Delayed Execution in Java? — IT Interview Guide

In Java, handling delayed execution is essential when building applications that require tasks to be executed after a specific delay or at fixed intervals. Whether it’s waiting for a few seconds before performing an action or scheduling recurring tasks, Java offers several tools to accomplish delayed execution efficiently. In this guide, we’ll cover a variety of methods to implement delayed execution, including Thread.sleep(), Timer, and ScheduledExecutorService. Let’s dive into these techniques with detailed explanations and code examples.

1. Using Thread.sleep() for Delayed Execution

One of the simplest ways to delay execution in Java is by using Thread.sleep(). This method pauses the execution of the current thread for a specified period of time, allowing for a delay before resuming the execution of the next statement. The time is passed as a parameter in milliseconds. Here's an example:

public class DelayedExecution { public static void main(String[] args) { try { System.out.println("Task started"); // Delaying execution for 3 seconds (3000 milliseconds) Thread.sleep(3000); System.out.println("Task executed after 3 seconds"); } catch (InterruptedException e) { e.printStackTrace(); } } }