java search file in folder

1import java.io.File;
2
3public class Main {
4   public static void main(String[] argv) throws Exception {
5      File dir = new File("directoryName");
6      String[] children = dir.list();
7      
8      if (children == null) {
9         System.out.println("does not exist or 
10         is not a directory");
11      } else {
12         for (int i = 0; i < children.length; i++) {
13            String filename = children[i];
14            System.out.println(filename);
15         }
16      }
17   }
18}