问题
The Thread should end if I press a button, which sets the isButtonPressed to true. My problem is, that if a want to start the thread with thread.start(runnable) by clicking the button, I get this: IllegalThreadStateException: Thread already started (I thought the thread was terminated after the break because the the loop is over, but it seems that I am wrong).
Thread thread = new Thread(runnable);
thread.start(runnable);
The runnable Runnable:
Runnable runnable = new Runnable() {
@Override
public void run() {
time = 10;
for (int i = 10; i <= 10; i--) {
handler.post(new Runnable() {
@Override
public void run() {
txt_Time.setText(String.valueOf(time));
}
});
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
if (isButtonPressed) {
break;
}
if (time == 0) {
resetVisibleState();
break;
} else {
time--;
}
}
}
};
Thanks for your help!
回答1:
Java threads are not restartable. For what you are trying to achieve, you could create a new thread each time, or you could look at an ExecutorService. Just create a single threaded executor (Executors.newSingleThreadExecutor), and submit your runnable to it every time you need it to run.
ExecutorService executor = Executors.newSingleThreadExecutor();
executor.submit(runnable);
回答2:
From my understanding you need to start a new thread. You cannot re-start a thread that has ran its course.
Since you are correctly stopping the old one via your isButtonPressed
. You should just be able to start a new instance of the thread in its place
回答3:
Take a boolean variable and wrap the contents you need to run continusly in the thread with a while loop that runs forever till Run is set to false then on clicking the button set the variable to false, for example :-
volatile boolean run = true;
Thread t = new Thread()
{
while(run)
{
// whatever is here runs till Run is false
}
}
t.start();
/*now when the button is pressed just trigger Run as false and the thread will be ended
later call t.start() when you need to start the thread again.*/
来源:https://stackoverflow.com/questions/35461897/stop-and-restart-a-already-running-thread