我正在寻找一种方法来阻止以下栏的进展:
private static void cancellaaaaaaaaable() throws InterruptedException {
System.out.println("Cancellaaaaaaable!");
System.out.print(ANSI_RED);
for(int i = 0; i < 79; i++){
// Something that allows user input/interaction capable to stop the progressbar
System.out.print("█");
TimeUnit.MILLISECONDS.sleep(500);
}
System.out.print(ANSI_RESET);
}
当进度条启动时,用户应该有大约40秒的时间来决定停止并取消进度条。
有办法吗?任何键盘输入都很棒,除了那些粗暴地停止这个过程的人。
答案 0 :(得分:3)
这是一个灵感来自how to read from standard input non-blocking?
的解决方案我们的想法是检查是否有来自System.in
的内容。
请注意,这仅在验证输入时有效(例如 Enter 键),但即使是空输入也可以( Enter 键直接按下),所以你可以添加一些&#34;按Enter取消&#34;消息。
private static void cancellaaaaaaaaable() throws InterruptedException {
System.out.println("Cancellaaaaaaable!");
System.out.print(ANSI_RED);
InputStreamReader inStream = new InputStreamReader(System.in);
BufferedReader bufferedReader = new BufferedReader(inStream);
for (int i = 0; i < 79; i++) {
System.out.print("█");
TimeUnit.MILLISECONDS.sleep(500);
// Something that allows user input/interaction capable to stop the progressbar
try {
if (bufferedReader.ready()) {
break;
}
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.print(ANSI_RESET);
}
请注意,您可以使用Java Curses Library执行更高级的控制台操作。
答案 1 :(得分:1)
定义一个Callable:
public Future<?> submit(Runnable task) {
if (task == null) throw new NullPointerException();
RunnableFuture<Object> ftask = newTaskFor(task, null);
execute(ftask);
return ftask;
}
然后是FutureTask和ExecutroService:
class MyCallable implements Callable<Boolean> {
@Override
public Boolean call() throws Exception {
for (int i = 0; i <= 99; i++) {
System.out.print("█");
try {
TimeUnit.MILLISECONDS.sleep(500);
} catch (InterruptedException e) {
e.getStackTrace();
return false;
}
}
return true;
}
}
并在需要时取消:
public static void main(String[] args) throws InterruptedException {
System.out.println("Cancellaaaaaaable!");
MyCallable callable1 = new MyCallable();
FutureTask<Boolean> futureTask1 = new FutureTask<>(callable1);
ExecutorService executor = Executors.newFixedThreadPool(1);
executor.execute(futureTask1);
TimeUnit.MILLISECONDS.sleep(500);
futureTask1.cancel(true);
System.out.println("\nDone");
}