Re: System property user.dir

From:
Lars Enderin <lars.enderin@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
Thu, 01 Mar 2007 13:09:01 GMT
Message-ID:
<45E6D06C.3020500@gmail.com>
Kunkhmer skrev:

On Mar 1, 5:55 am, "MikeB" <MPBr...@gmail.com> wrote:

in the Java API guide (http://java.sun.com/j2se/1.5.0/docs/api/java/io/
File.html) the docs mention a system property user.dir that supposedly
has the current user directory.

How do I access the value in this property?

Alternately, is there another way I can establish a base directory
such that, in a subdirectory of my package/jar, I can store data for
the application to read?

Eg. if my application is running in C:x\y\z, I'd like to have a
directory whose fully-qualified name is C:x\y\z\data. If the
application is transported and later runs on D:\a\b\c\, I'd like that
directory to resolve to D:\a\b\c\data.

Thanks.


Mike,

user.dir : is where you program is starting from
to get the value, just write this line

String basedir = System.getProperty("user.dir");

in your case, basedir will be "D:\a\b\c"
you need to do something like: basedir + "\data" to get an absolute
path.

To learn more, just run this small program.

/** start **/
import java.util.Enumeration;
import java.util.Properties;
public class Test {
    public static void main(String[] args) {
        Properties p = System.getProperties();
        Enumeration es = p.elements();
        while (es.hasMoreElements())
            System.out.println(es.nextElement());
    }
}
/** end **/


Smaller and better (also shows property names):

// Props.java
import java.util.Properties;
public class Props {
   public static void main(String[] args) {
     Properties p = System.getProperties();
     p.list(System.out);
   }
}

Compile: javac Props.java
Run: java -cp . Props

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