Daemon thread (background thread) and non-daemon thread (user thread, foreground thread)

After the current thread ends, the JVM will kill the background thread directly, and the background thread will not execute the contents of the finally code block

public class DemoThread implements Runnable {@Overridepublic void Run () {//TODO auto-generated method Stubtry {thread.cur Rentthread (). Sleep (1000); System.out.println ("I am a non-guardian thread");} catch (Interruptedexception e) {//TODO auto-generated catch Blocke.printstacktrace ();};}}

　　

public class Main {public static void main (string[] args) {ThreadStart ();} public static void ThreadStart () {DemoThread dt = new DemoThread (); Thread thread = new thread (dt); Thread.setdaemon (true); Thread.Start ();}}

1, when the direct start, will not print out the content

2. When Thread.setdaemon (true) is removed, "I am a non-Guardian thread" is printed.

Cause analysis: When the thread is set as the daemon thread, the main thread is the foreground thread, and after execution it ends directly, the JVM directly kill the thread of the daemon thread, the content of this daemon thread will not continue to execute; When the line is removed, thread defaults to the foreground thread. The JVM waits until all foreground threads have finished executing, and the thread thread prints out the content

Daemon thread (background thread) and non-daemon thread (user thread, foreground thread)