How to make it really read from a real file

are you using an IDE on your computer to run this (such as intelliJ); or are you using the online compiler? If you are using the online compiler then you won't be able to get an output.

also, just to be sure, TestTextDoc.txt does have data inside it? It isn't a blank text file?

I am guessing your code looks something like this:

public class Solution {
    public static List<String> lines = new ArrayList<String>();

    static {
        String line;
        try {
            FileReader fr = new FileReader(Statics.FILE_NAME);
            BufferedReader br = new BufferedReader(fr);
            System.out.println("Readers initialize, starting to read lines"); // add this #1
            while(br.ready()) {
                lines.add(br.readLine());
                System.out.println("\t***line read***"); // add this #2
            }
        }
        catch(Exception e) {
            System.out.println("Something went wrong with initialization and/or reading lines"); // add this #3
            e.printStackTrace();
        }

    }

    public static void main(String[] args) {
        System.out.println(lines);
    }
}

I suggest adding some Sys.out.println() in your code to see what is going on. In the above code I added one on lines 9, 12, and 16. This would show me if there is a problem with initializing the reader or if the actual reading of the lines is the problem. If there is a problem in the try block, such as the file not being found, then you can check the stacktrace (make sure to always print the stacktrace which is done on line 17 of my code) which will help with troubleshooting. Copy this method in your code (of adding the output lines) to help you get to debug problems.

Thank you very much for the advice! The addition of extra output lines helped to understand better what the code was doing. As for your questions, I'm using an IDE, my text file does contain four lines and, unfortunately, I'm not allowed to post my code here as the task is completed. For some reason, today my compiler agreed to open the file and output its content. However, it only displayed the 2nd and the 4th lines of the short poem in it (which contained four lines). I played with the code a bit and then changed my while-loop from while (breader.readLine() != null) to while (breader.ready()). The new loop started to display all the four lines from the source file. I'm not quite sure why the previous version of the while-loop saw the 1st and 3d lines in the text file as empty. And I still don't understand why my intellij idea couldn't read anything at all on Friday. Anyway, now it makes the output I want it to, and I understand the whole process better, thank you very much.

The .readLine() reads the next line in the file. Your first example, im gathering, probably looked similar to this:

while (breader.readLine() != null)
   System.out.println(breader.readLine());

In this case the .readline() in the while loop and the .readLine() in output were both reading data in the file. So, if you had 4 lines of data in the file then the first readLine() in the while loop read a line, checked that if was not null, then proceeded based on the result. If the result was true then the readLine() in the output would read the next line and output that. This results in every other line in the file being output. If you had an odd number of lines in the file then the final output would have been null.

You're second example fixed that because the ready() method returns true or false depending on if there are more lines to read from the file or not. Alternatively another way you can fix the first example is to save the result of the readline() method in a variable and use the variable, which is often the way that people do it:

String line; // create variable

// set variable to value of readLine(), check if that value is not null
while((line = breader.readLine()) != null)
   System.out.println(line); // output the variable

Oh, I see now! Thank you very much!