Tutorial 38 Reading Files with the File Reader

//Tutorial 38 Reading Files with the File Reader
//App.java
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

//You can read files using the scanner class(see previous tutorial 33) which is a bit less cumbersome,
//however, this is still important because you can change the code/adapt it so it will read files of all different formatss like the binary format.
//so what we are going to write here is very flexible despite cumbersome.
public class App {
    public static void main(String[] args) {
        File file = new File("text.txt"); //step 1.create new file

        BufferedReader br = null;

        try {
            FileReader fr = new FileReader(file);
            br = new BufferedReader(fr); //5. Do Buffering, right click on error, import what you need

            String line; //

            ///line = br.readLine();  //then click on error and add catch clause surround with try catch
                                                    //6. want a while loop so the App reads every line in the text.
            while( (line = br.readLine())!= null ){ //   want the while loop to stop reading when their are no more lines: "null"
            System.out.println(line);
            }



        } catch (FileNotFoundException e) {
            System.out.println("File not found: " + file.toString());
        } //2. read the file with FileReader
                                              //3.(ctrl+shift+O ) to import "import java.io.File; import java.io.FileReader;"
                                              ///it will throw a filenotfound exception, click the error and "surround it with trycatch"
        catch (IOException e) {
            System.out.println("unable to read file: " + file.toString());

        }
        finally { //finally block is always going to be executed everytime, even if exceptions are thrown
            try {
                br.close();
            } catch (IOException e) {
                System.out.println("unable to close file: " + file.toString());
            }
            catch(NullPointerException ex){
                //File was probably never opened!
            }
        }
    }

}
//---------------------------------------------------------------------------------------------------------------------------------------
//text.txt
first line
second line
third line
//---------------------------------------------------------------------------------------------------------------------------------------
/*Run Results:
first line
second line
third line
*/

//---------------------------------------------------------------------------------------------------------------------------------------
/*
Error Message (if u purposely get an error by switching the name of the text[ie: tefxt.txt) so it the program can't find the file):

File not found: tefxt.txt
*/


//note: there is a language feature in Java.7 that can simplify this exceptions nested mess: we will go over it in the next tutorial.