import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader; public class KeyinTest {
public static void main(String[] args) throws IOException {
var reader = new InputStreamReader(System.in);
var br = new BufferedReader(reader);
{
String line = null;
while ((line = br.readLine()) != null){
if (line.equals("exit")){
System.exit();
}
System.out.println("readline content:" + line);
} } }
}

output:

adddd
readline content:adddd
dasdf
readline content:dasdf
exit
04-03 09:14