Program throws NullPointerException when i try to search in drives?

Question

I wrote a program to find file or directory.
Its working properly when i am trying to Search file with in Directory
example
java FileSea

Answer 1

This is how you fix it:

import java.io.*;
class FileSearch{
static String fd;
static boolean flg=true;
public static void main(String arr[]){
    fd=arr[0];
    String path=arr[1];
    String dir[]=new File(path).list();
    new FileSearch().finder(dir,path);
    if(flg){System.out.print("File not found.");}
}
public void finder(String[] dir,String path){
    if(dir == null){
        return;
    }
    for(int i=0;i

Why? String dir[]=new File(path).list(); on the directory you specified is null so when you call dir.length you will get null pointer exception

another thing that will help you understand, System.out.print(new File(path).isDirectory()); if its false, then you will get null pointer exception.