java 父线程停止子线程,即使子线程的父线程死亡或终止，子线程仍如何执行？...

ゞ浴缸里的玫瑰 2022-10-04 12:51 138阅读 0赞

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Here are my two classes:

public class Firstclass \{

public static void main(String args\[\]) throws InterruptedException \{

System.out.println("Main start....");

Secondclass t1 = new Secondclass();

t1.setName("First Thread");

Secondclass t2 = new Secondclass();

t2.setName("Second Thread");

t1.start();

t2.start();

System.out.println("Main close...");

and

public class Secondclass extends Thread \{

@Override

public void run() \{

try \{

loop();

\} catch(Exception e) \{

System.out.println("exception is" + e);

public void loop() throws InterruptedException \{

for(int i = 0; i <= 10; i++) \{

Thread t = Thread.currentThread();

String threadname = t.getName();

if(threadname.equals("First Thread")) \{

Thread.sleep(1000);

\} else \{

Thread.sleep(1500);

System.out.println("i==" + i);

Now when I run Firstclass then the output is:

Main start....

Main close...

i==0

i==1

i==2

i==3

i==2

i==4

i==3

i==5

i==6

i==4

i==7

i==5

i==8

i==9

i==6

i==10

i==7

i==8

i==9

i==10

My question is: Let's consider main method is executed by a thread 'T' in JVM and t1 and t2 are obviously child threads of parent thread T so when T thread that is the main method dies how can T1 and T2 still execute and give us output. Because if parent thread dies or terminates then child thread should also die or terminate.

解决方案

There is no notion of a parent-child relationship between threads. Once the two threads are running they're basically peers. The main thread can exit while other thread still running.

Java has no real concept of "child" threads. When you start a thread it inherits the daemon and priority from the "parent" but that's the end of the parent/child relationship.

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