File and Scanner objects for opening and reading data in Java

My textbook states the following:

You can also use the Scanner class to read input from a file. Instead of passing System.in to the Scanner class constructor, you pass a reference to a File object. Here is an example:

File myFile = new File("Customers.txt");
Scanner inputFile = new Scanner(myFile);

The first statement creates an instance of the File class. The File class is in the Java API, and is used to represent a file. Notice that we have passed the string "Customers.txt" to the constructor. This creates a File object that represents the file "Customers.txt."

In the second statement, we pass a reference to this File object as an argument to the Scanner class constructor. This creates a Scanner object that uses the file "Customers.txt" as its source of input.

My question: I am unable to understand why do we need a File object? Can't we write the above code just as below to read files?

Scanner inputFile = new Scanner("Customers.txt");

If Java needs a File object and a Scanner object, how is it exactly working behind?

You need to pass the File object to the Scanner constructor to invoke Scanner(File source) constructor and not Scanner(String source) constructor. In case you use the string "Customers.txt" as the argument the constructor with the string as argument will be used and it will produce values scanned from the specified string as explained in the documentation and not from the file as you want.

What I believe is happening here is that the scanner class requires you to enter a primitive data type(aka String, int, etc.) and not a path.

Scanner inputFile = new Scanner("Customers.txt");

If you write the above code and display it, it will just be blank since the scanner class cannot understand your parameter. On the other hand, the class File takes in a path as a parameter and creates a file object that can be used as a parameter for the Scanner class. Hence why you have to create a file object before using the scanner class.