Which is better - using String or File as parameter type for methods that take filenames [closed]

Question

I have a couple of methods which take filenames as parameters. My doubt is that what is better way to declare the parameters of these methods.

• Should the parameter be of type String

  void normalizeData(String inFile)
  

• Or should I explicitly declare the parameter as File.

  void normalizeData(File inFile)
  

Personally I find File more intuitive but want to know about what is the best practice for such things.

Answer 1

I would pass an java.io.InputStream - this makes the code easier to test and doesn't bind it to the file system.

This way your code ends up like:

public void normalizeData(InputStream in)
{
  ...
}

And calling it:

myObject.normalizeData(new FileInputStream(myFile));

Or

myObject.normalizeData(new FileInputStream("c:/myfile.txt"));

Or in a test

myObject.normalizeData(new ByteArrayInputStream("some test data".getBytes()));