trouble with Scanner(new File("input"));

[ronyosi]

Hello,

I am having trouble with the File method, it gives the error, even though the files input1 and input2 are plain text files and located in the directory where it is executing....

"Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Unhandled exception type FileNotFoundException
Unhandled exception type FileNotFoundException

at compare.main(compare.java:9)

"

My code is:

import java.io.*;
import java.util.Scanner;

public class compare
{
public static void main(String[] args)
{
PrintStream output = System.out;
Scanner input = new Scanner(new File("input1"));
Scanner input2= new Scanner(new File("input2"));



int diffs=0;
while(input.hasNext())
{
if(input.next() == input2.next())
{
output.println("The characters are inconsistant");
diffs++;
}
}
if(diffs == 0)
{
output.println("These two text files are identical");
}
else
{
output.println(diffs + " Characters are inconsistant");
}


input.close();
input2.close();


}
}


thanks,
Ron

[Fubarable]

Quote:

are plain text files and located in the directory where it is executing

And this may be your very problem. This is likely not where Java is looking for your files. To find out where Java is looking, run this program from the same package:

Code:

import java.io.File;

public class Fubar1
{
  public static void main(String[] args)
  {
    File file = new File("Fubar.txt");
    System.out.println(file.getAbsolutePath());
  }
}

Also, when posting your code, please use code tags so that your code will retain its formatting and be readable. To do this, you place the tag [code] at the top of your block of code and the tag [/code] at the bottom, like so:

Code:

[code]
  // your code block goes here.
  // note the differences between the tag at the top vs the bottom.
[/code]

[ronyosi]

Hi,

thanks for the quick reply :-)
I am using eclipse. The files are in the src directory, and I also checked and saw that eclipse copied the very same files (input1 and input2) to the bin directory (where the compiled class files are when the interpreter runs them.

Cheers,
Ron

[ronyosi]

oh, sorry I misread what you wrote. I will try this now. :-)

[ronyosi]

Hi,

The method outputted:
/home/ronny/workspace/Textbook/Fubar.txt

Based on that (since the directories are the same), I tried moving the 2 files to the directory that was found, the error remains:

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Unhandled exception type FileNotFoundException
Unhandled exception type FileNotFoundException

at compare.main(compare.java:11)

Ron

[Fubarable]

so I assume that you put the files into the
"/home/ronny/workspace/Textbook/"
directory, correct? I'm confused. You are 100% sure that you are using the full file names, that you're not missing a simple extension such as ".txt" or something similar? It's probably a simple mistake here that we are both overlooking.

What you need to do is try to do something even simpler than what you are doing now. Just simply try to open a simple text file, read the lines and output them to the console as you read them. If you can get that working, then you will likely get this working.

[Eranga]

That's much better I think, working on a simple application. Seems to me he may do the same mistake again. Because on his past thread also, ask about FilwNotFoundException.

[sukatoa]

Quote:

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Unhandled exception type FileNotFoundException
Unhandled exception type FileNotFoundException

That means, the specific code block where the operation that deals with persisted data MIGHT throw a FileNotFoundException if that file doesn't exists, the compiler tells you that you have to catch such type of exception before running it....

or else, your program might behave badly....

that scenario may relate just like this,

Code:

public int logic(Object o){
     if(o.equals("hello")
          return 0;
}

The sample code will return 0 if the object equals to "hello",

The compiler will then ask you like this,
what if the object is not equal to hello? what value should that method return?