My java code is flawed, but i dont understand why

I am very new at java and my be missing something very basic. When i run my code i am trying to add value to accounts created in the code. When i try to run the code i recieve an error that a file cannot be found, but i thought that the file was created inside the code.

import java.util.Scanner;
import java.io.File;
import java.io.IOException;

class DoPayroll
{
public static void main(String args[])
                                    throws
        IOException     
{
    Scanner diskScanner =
        new Scanner(new File("EmployeeInfo.txt"));

    for (int empNum = 1; empNum <= 3; empNum++)
    {
        payOneEmployee(diskScanner);
    }
}

static void payOneEmpl开发者_运维问答oyee(Scanner aScanner)
{
    Employee anEmployee = new Employee();

    anEmployee.setName(aScanner.nextLine());
    anEmployee.setJobTitle(aScanner.nextLine());
    anEmployee.cutCheck(aScanner.nextDouble());
    aScanner.nextLine();
}
}

once run i recieve the following error

Exception in thread "main" java.io.FileNotFoundException: EmployeeInfo.txt (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:106)
at java.util.Scanner.<init>(Scanner.java:636)
at DoPayroll.main(jobexe.java:11)

i thought that in the above code using new Scanner(new File("EmployeeInfo.txt") would create the new file once i input a value. Please give me a simple solution and an explanation.

It will create a new file when you write to it. However to read from it, it must already exist. You might like to check it exists with

File file = new File("EmployeeInfo.txt");
if (file.exists()) {
    Scanner diskScanner = new Scanner(file);
    for (int empNum = 1; empNum <= 3; empNum++)
        payOneEmployee(diskScanner);
}

The File object can't find the filename you've passed. You either need to pass the full path of EmployeeInfo.txt to new File(...) or make sure current working directory is the directory that contains this file.

The File constructor does not create a file. Rather, it creates the information in Java needed to access a file on disk. You'd have to actually do file IO in Java using the created File for a new file to be created.

The Scanner constructor requires an existing File. So you need a full path to the real, valid location of EmployeeInfo.txt or to create that file using File I/O first. This tutorial on I/O in Java will help.

You are mistaking instantiating an instance of class File with actually writing a temp file to Disk. Take this line

Scanner diskScanner =
        new Scanner(new File("EmployeeInfo.txt"));

And replace it with this

File newFile = File.createTempFile("EmployeeInfo", ".txt");
Scanner diskScanner = new Scanner(newFile);

Edit: Peter makes a good point. I'm face palming right now.

You thought wrong :D A Scanner needs a existing file, which seems quite logical as it reads values and without a existing file its difficult to read. The documentation also states that:

Throws: FileNotFoundException - if source is not found

So, in short: You must provide a readable, existing file to a scanner.

As the other answer explain, the file is not created just by using new File("EmployeeInfo.txt"). You can check is the file exists using

File file = new File("EmployeeInfo.txt");
if(file.exists()) {
  //it exists
}

or you can create the file (if it doesn't exists yet) using

file.createNewFile();

that method returns true if the file was created and false if it already existed.