In this post, we will see Thread life cycle in Java. There are five states of a thread as below.
- New
- Runnable
- Running
- Non-Runnable (Waiting)
- Dead
New – The thread is in new state if you create an object of Thread class.
package multithreading;
class Thread1 extends Thread {
}
public class ThreadLifeCycleExample {
public static void main(String[] args) {
Thread1 thread = new Thread1();
}
}
Runnable – The thread is in the runnable state after the invocation of start() method, but the thread scheduler has not selected it to be the running thread.
package multithreading;
class Thread1 extends Thread {
}
public class ThreadLifeCycleExample {
public static void main(String[] args) {
Thread1 thread = new Thread1();
thread.start();
}
}
Running – The thread is in running state if the thread scheduler has selected it. Now run() method will be invoked.
package multithreading;
class Thread1 extends Thread {
public void run() {
for (int i = 0; i < 5; i++) {
System.out.println("Thread1 is in running state with name: - " + Thread.currentThread().getName());
}
}
}
public class ThreadLifeCycleExample {
public static void main(String[] args) {
Thread1 thread = new Thread1();
thread.start();
}
}
Non-Runnable (Waiting) – This is the state when the thread is in waiting state.
package multithreading;
class Thread1 extends Thread {
public void run() {
for (int i = 0; i < 5; i++) {
System.out.println("Thread1 is in running state with name: - " + Thread.currentThread().getName());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public class ThreadLifeCycleExample {
public static void main(String[] args) throws InterruptedException {
Thread1 thread = new Thread1();
thread.start();
}
}
Dead- A thread is in the terminated or dead state when it’s run() method exits.
