Difference between JAVA daemon thread and user thread

Difference between JAVA daemon thread and user thread

 

public class DaemonTest {    public static void main(String[] args) {        new WorkerThread().start();        try {            Thread.sleep(7500);        } catch (InterruptedException e) {}        System.out.println("Main Thread ending") ;    }}class WorkerThread extends Thread {    public WorkerThread() {        setDaemon(true) ;   // When false, (i.e. when it's a user thread),                // the Worker thread continues to run.                // When true, (i.e. when it's a daemon thread),                // the Worker thread terminates when the main                 // thread terminates.    }    public void run() {        int count=0 ;        while (true) {            System.out.println("Hello from Worker "+count++) ;            try {                sleep(5000);            } catch (InterruptedException e) {}        }    }}

Easy to understand: the daemon does not prevent JVM shutdown. When a user runs a thread, the JVM cannot be disabled. When no user thread is running, it doesn't matter if there is a daemon thread. JVM will shut down.

 

Example of a daemon application: java garbage collection. When no thread is running, no garbage is generated, and the garbage collection does not function. JVM can be disabled.

Background of the daemon thread application: Background threads (for example, threads that can collect certain system states, threads that send emails, and other things that do not want to affect JVM)