how to delete a directory

843798

Hi all,
I am trying to delete a directory using my java code as,

import java.io.*;

class dirinfo {
public static void main(String s[]){
deldir(s[0]);
}

public static void deldir(String st){
File f= new File(st);
if (f.isFile())
{
try{
Runtime.getRuntime().exec("del " + f.getAbsolutePath() );
return;
} catch(IOException e) {System.out.println("EXCEPTION: " + e);}
}

String[] fl= f.list();
for (int i=0;i<fl.length;i++)
deldir(fl);
}
}

It compiles without error. On giving a command like,
java dirinfo c:\test or c:\\test,
my test directory in c: doesnt have dirinfo.java/class file.
i get the following error:-

EXCEPTION : java.io.IOException CreateProcess del
d:\html\fileinfo.java error=0
Exception in thread "main"
java.lang.NullPointerException
at dirinfo.deldir(dirinfo.java:19)
at dirinfo.deldir(dirinfo.java:20)
at dirinfo.main(dirinfo.java:5)

Can anyone help???

thanx,
john.

843798

String[] fl= f.list();
for (int i=0;i<fl.length;i++)

if fl is null, then doing fl.length will indeed give you a:

java.lang.NullPointerException
at dirinfo.deldir(dirinfo.java:19)
at dirinfo.deldir(dirinfo.java:20)
at dirinfo.main(dirinfo.java:5)

Instead, try adding this:

String[] fl= f.list();
if (fl!=null){
    for (int i=0;i<fl.length;i++)
        deldir(fl);
}

843798

thanx a lot. yes u were right. i checked for null now its fine. but still i have a problem with Runtime.getRuntime.exec('c:\\windows\\command.com/c del " + f.getPath() + "\\" + f);

what am trying to do here is to delete the file by getting its path. am working on windows ME. do u have any idea? the error am getting is,
Exception java.io.IOException CreateProcess : filename.java\filename.java error=0

here filename is 'fileinfo.java' as in my test directory.

843798

Unless you have a specific reason not to do so, you'd probably be better off using the methods in the java.io.File class - it has its own delete() method which you can use on files and/or directories, and it is platform independent. Take a look at the API javadoc

843798

under dos ( windows ) you can not "del" a directory.
you need to use "rmdir"
kurt

843798

Hi all,
I got the solution for deleting of directory. the code is :

import java.util.zip.*;
import java.util.jar.*;
import java.io.*;

class dirinfo
{
public static void main(String s[])
{
deldir(s[0]);
System.out.println("DELETION COMPLETE.....!");
}

public static void deldir(String st)
{
File f= new File(st);


if (f.isFile())
{
f.delete();
return;
}


String[] fl=f.list();
if (fl!=null && fl.length >0)
{
for (int i=0;i<fl.length;i++)
{

File f1= new File(f.getPath() + "\\" + fl);
if(!f1.isFile())
{
deldir(f1.getPath());
}
else
{
deldir(f.getPath() + "\\" + fl[i]);
}
}

System.out.println("Deleting empty dir 1
..."+ f.getPath());
File f1=new File(f.getPath()); f1.delete(); return;


} //-------if
File f1=new File(f.getPath()); f1.delete(); return;
}


}


THANX FOR ALL THE HELP
:-)

843798

I like to know the answer too.

regards