I've implemented a thread that get user input by keyboard. However, when user sets input my program returns an IllegalThreadStateException error, at line 23.
import java.util.Scanner;
public class Main {
static MyThread myThread = new MyThread();
static public boolean answered = false;
public static void main(String[] args) {
String s = "";
while (!s.equalsIgnoreCase("q")) {
int seconds = 0, average = 5;
if (seconds > average) {
myThread.stop();
String phrase = choosePhrase(seconds, average);
System.out.println(phrase);
Scanner keyboard = new Scanner(System.in);
s = keyboard.nextLine();
} else {
long createdMillis = System.currentTimeMillis();
myThread.start();
while (!answered && seconds < average) {
long nowMillis = System.currentTimeMillis();
seconds = (int) ((nowMillis - createdMillis) / 1000);
}
}
}
}
private static String choosePhrase(int seconds, int average) {
if (seconds > average 10) {
return "¿D?";
} else if (seconds > average 5) {
return "¿E?";
} else {
return "¿F?";
}
}
}
class MyThread extends Thread {
static String[] questions = {"¿A?", "¿B?", "¿C?"};
public void run() {
System.out.println("MyThread running");
Double d = Math.random() * 100;
int n = (int) (Math.ceil(d) % 3);
String question = questions[n];
System.out.println(question);
Scanner keyboard = new Scanner(System.in);
String s = keyboard.nextLine();
stop();
}
}
Why am I getting this exception? How do I make the thread gets and exits correctly to main function?
CodePudding user response:
To make a thread exits proprely you have to use myThread.interrupt();
CodePudding user response:
I've solved the issue with your suggestions:
import javax.swing.JOptionPane;
public class Main {
public static void main(String[] args) {
Latency latency = new Latency();
latency.start();
}
}
class Latency {
int seconds = 0, average = 5;
MyThread myThread;
ObjectToPass o = new ObjectToPass();
public void start() {
String s = "";
Thread t = null;
while (!s.equalsIgnoreCase("q")) {
// The program has just begun, or user has answered a question,
// or term has expired.
seconds = 0;
if (myThread != null) {
myThread.shutdown();
myThread = null;
}
if (o.answered) {
o.answered = false;
myThread = new MyThread(o, new String[]{"¿A?", "¿B?", "¿C?"});
} else {
myThread = new MyThread(o, new String[]{"¿D?", "¿E?", "¿F?"});
}
t = new Thread(myThread);
t.start();
long createdMillis = System.currentTimeMillis();
while (!this.o.getPlay() && seconds < average) {
long nowMillis = System.currentTimeMillis();
seconds = (int) ((nowMillis - createdMillis) / 1000);
}
}
}
}
class ObjectToPass {
boolean answered = true;
public synchronized boolean getPlay() {
return answered;
}
public synchronized void setPlay(boolean answered) {
this.answered = answered;
}
}
class MyThread implements Runnable {
ObjectToPass o;
static String[] questions;
public MyThread(ObjectToPass o, String[] questions) {
this.o = o;
this.questions = questions;
}
public void run() {
// System.out.println("MyThread running");
Double d = Math.random() * 100;
int n = (int) (Math.ceil(d) % 3);
String question = questions[n];
System.out.println(question);
// Scanner keyboard = new Scanner(System.in);
// String s = keyboard.nextLine();
Object[] options = {"Yes", "No"};
int oo = JOptionPane.showOptionDialog(null,
question, "Question", JOptionPane.YES_OPTION,
JOptionPane.NO_OPTION, null, options, options[0]);
this.o.setPlay(true);
}
public void shutdown() {
Thread.currentThread().interrupt();
return;
}
}