clear screen option in java [duplicate]

Answer 1

For any console which supports ANSI escapes the following would work (would e.g. work in Win98 console).

private final String ANSI_CLS = "\u001b[2J";
....
System.out.print(ANSI_CLS);
System.out.flush();
...

Starting with Win NT this won't work anymore and you can either

• Do a JNI call (e.g. like here: Java: Clear console and control attributes
• Or write out a bunch of empty lines

Otherwise you are out of luck.

And btw. you must keep in mind that System.out and System.err don't have to be console they could be set to what ever (writing into a file e.g.) an usecase where clearing the screen wouldn't make any sense at all.

Answer 2

Jansi is an excellent workaround. I am an amateur coder and Jansi is easy to setup especially with Eclipse.

The following is a link to the homepage of Jansi:

http://jansi.fusesource.org/

The following is a link to a site containing a code as a demonstration of AnsiConsole class contained in the Jansi package:

http://www.rgagnon.com/javadetails/java-0047.html

Answer 3

You can also try ANSI Escape Codes:

If your terminal support them, try something like this:

System.out.print("\033[2J\033[1;1H");

You can include \0333[1;1H to be sure if \0333[2J does not move the cursor in the upper left corner.

More specifically:

• 033 is the octal of ESC
• 2J is for clearing the entire console/terminal screen
• 1;1H moves the cursor to row 1 and column 1

Answer 4

As dirty hacks go, I like msparer's solution. An even dirtier method that I've seen used (I would never do this myself. I swear. Really.) is to write a bunch of newlines to the console. This doesn't clear the screen at all, but creates the illusion of a clear screen to the user.

char c = '\n';
int length = 25;
char[] chars = new char[length];
Arrays.fill(chars, c);
System.out.print(String.valueOf(chars));

Answer 5

you should give a try with JNA and try mapping native libraries:

• on linux you must map C functions from ncurses library
• on windows you must map functions from both msvcrt and kernel32, as clearly stated here

PS

let me known if you need some sample code

Answer 6

If you're talking about a console application, then there isn't a clear screen option AFAIK. A quite dirty option would be to invoke the clear screen command of the underlying OS.

Then it's something like

Runtime.getRuntime().exec("cls");

for Windows or

Runtime.getRuntime().exec("clear");

for a load of other OS. You can find out the OS with System.getProperty("os.name").