In IntelliJ IDEA, I couldn't send input while the debug mode reaches the line
String i = in.nextLine();
which is waiting for user input.
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The screenshot is as follows.
Looks like your console is hidden in debug mode. See the right most icon with >
symbol right next to profiler. click on it and it must open the console.
Another way is right click on Debugger and choose Layout and check mark Console
.