如何在java中读取不以新行或回车字符结尾的行？

Question

I am using BufferedReader as follows,

BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
for (int i = 0; i < 4; i++) {
   System.out.println(stdin.readLine());
}

And the input given is as follows,

1
2
3

The last input doesn't end with \\n or \\r , therefore for 3 readLine() will expect input from user unless user presses enter key

Any solution for this using Scanner ?

Actually, I got into this problem while solving , Quora Question Nearby , In their conditions they have mentioned following lines,

Does the last line in the input test case end with a newline? [link]

Nope. No trailing spaces or newlines.

---

Link for Code , Submitted at above page, test cases are failing

For Test Case Zero, It shows following output , Since, expected output is blank, it means my codes still expects \\n or \\r which is not provided by input

Answer 1

If the input is terminated - which would be the case if standard input is actually being redirected from a file, for example - then it's fine. BufferedReader.readLine will still return the last line from its input, when it detects the end of the underlying data.

Given that this is an automated challenge, I would expect this to be the case - I'd expect it to be run as something like

java Solution < input.txt

So basically, I believe you should be fine.

Answer 2

If you want to get the output without pressing enter,it is impossible. Because System.in stream doesn't allow you to take input without pressing enter by default.You have to use a third party library like JNI for that.