what is runtime.getruntime().exec("domain specific equivalent of cls") for windows 7

Question

I want to clear screen in my java application, after reading many questions and googling, I found the below code

runtime.getruntime().exec("cls")

or

Runtime.getRuntime().exec("cmd /c cls");

but the above code doesn't work in windows 7. I am aware the "cls" script is domain specific, does anyone know what is the text I should use in windows 7. it will be really helpful, thank you in advance.

It would be a lot simpler to just write the ANSI escape sequences for 'Home' and 'Clear to EOS' to System.out. — user207421, Feb 21 '13 at 12:25

paxdiablo · Answer 1 · 2013-02-22T17:28:18.287

2

Since cls is an internal command (something cmd.exe does itself rather than calling an executable program), you can do it with:

cmd /c cls

This works fine under Windows 7, assuming you're actually running a console-type application.

edited Feb 22 '13 at 17:28

answered Feb 21 '13 at 12:15

paxdiablo

854,327
234
1,573
1,953

am gonna try this, but it looks like one of the many combinations I tried before. – Radan Feb 21 '13 at 13:37
Runtime.getRuntime().exec("cmd /c cls"); dint work got IO exception as usual. – Radan Feb 21 '13 at 17:11
1

@Radan You need to pass the parameters as a string array, see this: http://stackoverflow.com/questions/3608944/adding-parameters-to-runtime-getruntime – lbalazscs Feb 22 '13 at 15:08
1

it still doesn't work here with: ```String[] command = new String[] {"cmd.exe", "/c", "cls"}; Runtime.getRuntime().exec(command);``` – Redoman Apr 24 '14 at 21:36
I can confirm that this didn't work for me either on Win7. I also tried: `String[] command = new String[] {"C:\\Windows\\System32\\cmd.exe", "/c", "cls"}; Runtime.getRuntime().exec(command);` There is no error given, the line just looks like it's skipped. – localhost Feb 09 '15 at 11:53
@localhost: it doesn’t work, even when there are no errors, because when running sub-processes this way, the output of of the command gets redirected. See [here](http://stackoverflow.com/a/33379766/2711488) – Holger Oct 28 '15 at 09:46

Java42 · Accepted Answer · 2013-02-22T19:52:51.097

I realize you are looking for an easy way to clear the screen. You will have to use the newline hack or use an ANSI enabled console. Here is a little more difficult windows only method using JNA you or others reading this can consider. This is an instructional example. Add error checking/handling/imports/includes as necessary. You must already know how to use JNA. If you are new to JNA, this is a good 1st program for you to try.

//------------------------------------------
// Java2Win.class
//------------------------------------------
public interface Java2Win extends Library {
    Java2Win java2Win = (Java2Win)Native.loadLibrary("Java2Win64",Java2Win.class);
    void cls();
}
//------------------------------------------

//------------------------------------------
// Java2Win.c (Java2Win.dll & Java2Win64.dll)
//------------------------------------------
JNIEXPORT void cls() {
   system("cls");
}
//------------------------------------------

//------------------------------------------
// Test
//------------------------------------------
public static void main(final String args[]) throws Exception {
    final File file = new File("rootToDLL", "Java2Win64.dll");
    LibraryLoader.loadLibrary(file);
    System.out.println("-----some output");
    System.out.println("-----some output");
    System.out.println("-----some output");
    Thread.sleep(2000);
    Java2Win.java2Win.cls();
    System.out.println("-----cleared");
}
//------------------------------------------

what is runtime.getruntime().exec("domain specific equivalent of cls") for windows 7

2 Answers2