What Are the Different Thread States in Java with Code Examples? — IT Interview Guide

What Are the Different Thread States in Java with Code Examples?

In Java, thread management is a critical concept for building efficient, high-performance applications. The java.lang.Thread class provides built-in support for multithreading, and understanding the Thread lifecycle is essential to effectively utilize these capabilities.

Java threads can exist in the following states as defined in the Thread.State enum:

Let’s explore each state with detailed explanations and code examples to bring the concept to life.

1. NEW

A thread is in the NEW state when it is created but not yet started.

Thread t = new Thread(() -> {
    System.out.println("Running thread");
});
System.out.println(t.getState()); // Output: NEW

Explanation: The thread object is instantiated, but start() has not been invoked.

2. RUNNABLE

A thread is in the RUNNABLE state after the start() method is called and before it enters the waiting or terminated states.

Thread t = new Thread(() -> {
    while(true) {
        // Simulating work
    }
});
t.start()…