按下按钮时读取一行

Question

I have to do a quiz class that will read the questions from a text file, I am stuck trying to make the program work in such way that every time the answer button is pressed it reads the next question (line in the text file), I tried many suggestions from the internet but the furthest i got was to read the first line when the program runs then using String[] args = new String[0]; to have a new frame when the button is pressed but then the text wouldn't read at all.

Here is my code:

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Frame {

    JFrame frame;
    JPanel pan1;
    static JButton boutonRetour,boutonEnregistrer;
    static JTextField reponse,question;
    static int counter1 = 1;
    static int lines=0;


    public static void main(String[] args) {

        final JFrame frame = new JFrame("Frame");

        frame.setSize(700,600);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        frame.setVisible(true);
        question=new JTextField(10);
        question.setBounds(150, 220, 450, 50); 
        question.setEditable(true);
        frame.setContentPane(new JPanel() {
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.drawImage(null, 0, 0, 700, 600, this);
            }
        });

        boutonEnregistrer=new JButton("Answer");
        boutonEnregistrer.setBounds(0,513,100,50);

        boutonEnregistrer.setBackground(new Color(0, 0, 182));
        boutonEnregistrer.setForeground(Color.white);
        boutonEnregistrer.setFocusPainted(false);
        boutonEnregistrer.setFont(new Font("Tahoma", Font.BOLD, 12));

        boutonEnregistrer.addActionListener(new ActionListener(){ 

            public void actionPerformed (ActionEvent e){
                counter1++;  
                String[] args = new String[0];              

                main(args); 
                /*
                SwingUtilities.updateComponentTreeUI(frame);
                frame.revalidate();
                frame.repaint();
                frame.removeAll();
                frame.invalidate();
                frame.validate();
                */   
            } 
        });


        frame.add(question);        
        frame.add(boutonEnregistrer);
        frame.setLayout(null);
        System.out.println(counter1);


        try {        
            BufferedReader br =
            new BufferedReader(new FileReader("Questions.txt"));
            String word = null;
            while((word =br.readLine()) != null) {
                lines++;
            if (lines == counter1){
                question.setText(word);
                break;

}

            }

        } catch(IOException err) {

        }                          
        frame.validate();
        System.out.println(lines);

    };
}

Answer 1

You use the lines variable to keep track of the last line that was read. However that is not happening in your code. The while loop always runs until the reader reaches EOF.

You should break from the loop once you read the desired line:

if (lines == counter1){
    question.setText(word);
    break;
}