Java wait() vs sleep() with Examples

Ramesh Fadatare

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4 min read

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Apr 5, 2025

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In Java multithreading, both wait() and sleep() methods are used to pause the execution of a thread. However, they are completely different in terms of behavior, purpose, and usage.

Understanding the difference between wait() and sleep() is essential for writing thread-safe and efficient concurrent code. Let’s explore each method in depth with examples and explain how they differ point by point.

Overview of wait() and sleep()

What is wait()?

• wait() is a method of the java.lang.Object class.
• It is used for inter-thread communication.
• When a thread calls wait(), it releases the lock it holds and waits until another thread calls notify() or notifyAll() on the same object.

What is sleep()?

• sleep() is a method of the java.lang.Thread class.
• It is used to pause the current thread for a specific period of time.
• The thread does not release the lock during sleep and resumes automatically after the sleep duration is over.

📊 Comparison Table: wait() vs sleep()

Let’s go deeper into each point and illustrate it with examples.