File.listFiles...doesn't return the files from the sub directory...

[kay lin]

I did create a class that implements the FileFilter,
but it only returns the XML files from the current directory, not the sub directory...

What should I do if I want it to return the XML files from the subdirectory as well? here is my code

 public class XMLFilter implements FileFilter {
  public XMLFilter() {
  }
 
  public boolean accept(File pathname) {
    /**@todo Implement this java.io.FileFilter method*/
    return pathname.getAbsolutePath().endsWith("xml");
 
  }
 
} 

and here is my Test class that I test them out

 public class XMLFilter implements FileFilter {
  public XMLFilter() {
  }
 
  public boolean accept(File pathname) {
    /**@todo Implement this java.io.FileFilter method*/
    return pathname.getAbsolutePath().endsWith("xml");
 
  }
 
}   XMLFilter xf = new XMLFilter();
    File[] list = f.listFiles(xf);
 
    for(int i=0;i<list.length;i++){
      System.out.println("hello " + list[i].getAbsolutePath());
    }
 
  } 

Any ideas?

Thanks

[Ernest Friedman-Hill]

Some of the File objects in the current directory represent subdirectories. To list all the .xml files in this directory and all the subdirectories, you have to

1. Add all the XML files in the current directory to the list.
2. For each subdirectory, go to step 1.

It's most natural to implement this using recursion.

[kay lin]

yeah..that is exactly what i did, only I didn't check your reply on time

Many thanks regardless

[kay lin]

but I think I'd also like to point out one thing though,

if the project directory you are working in has multiple sub folders, wouldn't you potentially run into a stack overflow exception?


i guess this could still work for a normal project directory that has no more than 3 sub levels...

[Ernest Friedman-Hill]

Yes, recursion always runs the risk of stack overflow. It's possible to implement this using an iterative method and an explicit stack (this is true of any recursive algorithm.) Push the initial directory onto a java.util.Stack. Then

while the stack is not empty {
  1. pop a directory off the stack
  2. add the *.XML files from the directory to the list
  3. push every subdirectory onto the stack
}