Reading a single char in Java

Using nextline and System.in.read as often proposed requires the user to hit enter after typing a character. However, people searching for an answer to this question, may also be interested in directly respond to a key press in a console!

I found a solution to do so using jline3, wherein we first change the terminal into rawmode to directly respond to keys, and then wait for the next entered character:

var terminal = TerminalBuilder.terminal()
terminal.enterRawMode()
var reader = terminal.reader()

var c = reader.read()
<dependency>
    <groupId>org.jline</groupId>
    <artifactId>jline</artifactId>
    <version>3.12.3</version>
</dependency>

You can either scan an entire line:

Scanner s = new Scanner(System.in);
String str = s.nextLine();

Or you can read a single char, given you know what encoding you're dealing with:

char c = (char) System.in.read();

You can use Scanner like so:

Scanner s= new Scanner(System.in);
char x = s.next().charAt(0);

By using the charAt function you are able to get the value of the first char without using external casting.

Tags:

Java