run setx command using java

Question

I am writing a java code that will append a path string to the %PATH% variable using java

In command prompt the command is

setx PATH "%PATH%;C:\my Path\"

In java here is my code:

import java.io.File;
import java.io.IOException;

public class AddToPATHVariable {
    public static void main(String[] args) throws InterruptedException, IOException {
        String folderPath = "C:\\my Path\\";
        System.out.println(folderPath);
        Runtime rt = Runtime.getRuntime() ;
        Process p = rt.exec("setx PATH \"%PATH%;" + folderPath + "\"");
        p.waitFor();
        p.destroy();
    }

}

The issue is that my command line prompt is append the new string perfectly. But java code is make the value to path variable to be %PATH%;C:\my Path\

someone please guide me in this regard.

are you talking about double backslash (\\ ) converting to Single backslash? — Pramod S. Nikam, Aug 08 '14 at 11:25
@NutterzUK I mean the the previous path value is replace my hardcoded string %PATH% — Javeria Habib, Aug 08 '14 at 11:49
@Orion...no, I mean the the previous path value is replace my hardcoded string %PATH% — Javeria Habib, Aug 08 '14 at 11:49

Serge Ballesta · Answer 1 · 2014-08-15T08:23:24.690

2

Well, as nothing is in charge of converting %PATH% it simply is not converted !

More seriously, it is the cmd.exe interpretor that actually does the translation of environment variables and you do not use it. To have it to work, you must :

convert the environment variable PATH to its value in java code
```
String path = System.getenv("PATH");
```

use the converted String in your command

Process p = rt.exec("setx PATH \"" + path + ";" + folderPath + "\"");

EDIT :

To really be sure of what happens, you can display the generated command before executing it :

String cmd = "setx PATH \"" + path + ";" + folderPath + "\"";
Process p = rt.exec(cmd);

edited Aug 15 '14 at 08:23

answered Aug 08 '14 at 16:06

Serge Ballesta

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I do the same...and even have debugged it but in the end result, it appends some part from the start of the original path instead of the folderpath. – Javeria Habib Aug 15 '14 at 06:15
getenv is returning the PATH variable 3 times – Javeria Habib Aug 15 '14 at 07:23
@JaveriaHabib I updated my anwser to be sure of the executed command. But beware : setx modify the environment for **futures** windows command, not for current one. Look at `setx /?` it should say something like : *in an local system, variables created or changed by this tool will be used by future command windows, but not in current CMD.EXE window* (translation is mine, my system speaks french :-) ) – Serge Ballesta Aug 15 '14 at 08:20

run setx command using java

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