FileHandler

import java.util.Scanner;
import java.io.IOException;
import java.io.File;
import java.io.FileWriter;
import java.io.FileNotFoundException;
import java.io.BufferedWriter;

/**
 * Contains methods for creating, reading from, writing and appending to text files.
 *
 * @author (Ruari Mears)
 * @version (04.10.2021)
 */
public class FileHandler
{
    private Scanner scanner;

    /**
     * Constructor for objects of class FileHandler
     */
    public FileHandler()
    {
        scanner = new Scanner(System.in);
    }

    private String getFilename() {
        Scanner scanner = new Scanner(System.in);
        System.out.println();
        System.out.println("Please specify the filename:");
        String filename = scanner.next();

        return filename;
    }

    /**
     * Source: https://www.w3schools.com/java/java_files_create.asp
     *
     * To create a file in Java, you can use the createNewFile() method.
     * This method returns a boolean value: true if the file was successfully created, and false if the file
     * already exists. Note that the method is enclosed in a try...catch block. This is necessary because it
     * throws an IOException if an error occurs (if the file cannot be created for some reason)
     */
    public void createFile() {
        String filename = getFilename();
        //String path = "..\\FileHandling\\";
        try {
            //File file = new File(path + filename);
            File fileObject = new File(filename);
            if (fileObject.createNewFile()) {
                //System.out.println("File created: " + file.getName());
                System.out.println(fileObject.getName());
            } else {
                System.out.println("File already exists.");
            }
        } catch (IOException e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }
    }

    public void readFromFile() {
        try {
            String filename = getFilename();
            File fileObject = new File(filename);
            Scanner myReader = new Scanner(fileObject);
            while (myReader.hasNextLine()) {
                String data = myReader.nextLine();
                System.out.println(data);
            }
            myReader.close();
        } catch (FileNotFoundException e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }
    }

    /**
     * Source: https://www.w3schools.com/java/java_files_create.asp
     *
     * In the following example, we use the FileWriter class together with its write() method to write some
     * text to the file we created in the example above.
     * Note that when you are done writing to the file, you should close it with the close() method.
     */
    public void writeToFile() {
        try {
            String filename = getFilename();
            FileWriter fileWriter = new FileWriter(filename);
            fileWriter.write("Writing to files in Java might seem tricky, but it is easy enough!");
            fileWriter.close();
            System.out.println("Successfully wrote to the file.");
        } catch (IOException e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }
    }

    /**
     * Source: https://www.tutorialspoint.com/Java-Program-to-Append-Text-to-an-Existing-File
     *
     * Uses the Java.io.BufferedWriter class writes text to a character-output stream, buffering characters so
     *  as to provide for the efficient writing of single characters, arrays, and strings.
     *
     * To add contents to a file:
     *
     * - Instantiate the BufferedWriter class.
     * - By passing the FileWriter object as an argument to its constructor.
     * - Write data to the file using the write() method.
     */
    public void appendToFile() {
        try {
            String filename = getFilename();
            String data = "\n" + "This is a line of new text added " + java.time.LocalDate.now() + " "
                + java.time.LocalTime.now();
            File fileObject = new File(filename);
            if(!fileObject.exists()) {
                fileObject.createNewFile();
            }

            FileWriter fileWritter = new FileWriter(fileObject.getName(),true);
            BufferedWriter bufferedWriter = new BufferedWriter(fileWritter);
            bufferedWriter.write(data);
            bufferedWriter.close();
            System.out.println("Done");
        } catch(IOException e){
            e.printStackTrace();
        }
    }
}