Final answer:
Daemon threads in Java are background threads that perform housekeeping or service tasks and do not prevent the JVM from exiting once all user threads are done. They are created using setDaemon(true) before the thread starts. They are intended for non-critical tasks and can be abruptly terminated.
Step-by-step explanation:
Key Points on Daemon Threads in Java
A daemon thread in Java is a low-priority thread that runs in the background to perform tasks such as garbage collection, or to provide services to user threads. Daemon threads are not meant to prevent the JVM from exiting once all user threads have finished their execution. Here are some critical points to remember about daemon threads:
- User threads are the high-priority threads that keep the Java Virtual Machine alive and are used to perform the main operations of an application.
- A daemon thread is created by calling the setDaemon(true) method before the thread is started.
- A daemon thread will not prevent the JVM from exiting once all user threads have finished executing, and it dies as soon as all user threads are complete.
- Since daemon threads should not be used for critical tasks, as they may not finish executing before the JVM exits.
- Tasks performed by daemon threads should be short and of low importance to the overall functioning of the application.
It's essential to use daemon threads appropriately to ensure a Java application functions as intended without any unexpected behavior.