单击下一个按钮时显示下一个问题

Question

我正在尝试读取 java 中的文件。单击下一步按钮时，如何在单击下一步按钮时显示第二个问题？

我的.txt文件内容是这样的

1. What is his name
A.John
B.David

2. How old is him?
A.24
B.27

到目前为止，我可以在 JTextField 中显示第一个问题。

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.File;
import java.io.FileReader;


public class NewJFrame extends javax.swing.JFrame {

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() throws IOException {
        initComponents();
        setLocationRelativeTo(null);
        pack();
        File file = new File("/home/xxx/Desktop/englishQuestion.txt");
        StringBuilder sb = new StringBuilder();

        try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line).append("\n");
                if (line.equals("")) {
                    break;
                }
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
        String result = sb.toString();
        jTextArea1.setText(result);
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton1 = new javax.swing.JButton();
        textField1 = new java.awt.TextField();
        label1 = new java.awt.Label();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("Next");

        textField1.setName("\"\""); // NOI18N
        textField1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                textField1ActionPerformed(evt);
            }
        });

        label1.setText("Answer:");

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(0, 0, Short.MAX_VALUE)
                .addComponent(label1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 53, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 57, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(28, 28, 28))
            .addGroup(layout.createSequentialGroup()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 421, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 206, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(label1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jButton1))
                .addContainerGap())
        );

        label1.getAccessibleContext().setAccessibleName("Answer: ");

        pack();
    }// </editor-fold>                        

    private void textField1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
        // TODO add your handling code here:
    }                                          

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    new NewJFrame().setVisible(true);
                } catch (IOException ex) {
                    Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea jTextArea1;
    private java.awt.Label label1;
    private java.awt.TextField textField1;
    // End of variables declaration                   
}

Answer 1

首先，你在文件中的问题应该是统一的格式，我的意思是我们应该能够区分不同的问题和它的选项。

其次，然后您阅读每个问题及其选项并将其存储在 Java 对象中。假设问题对象。

问题对象可能如下所示：-

class Question {
   String questionString;
   String[] options;
}

然后，你读取每个question/options并形成一个Object之后，你将这些对象存储在一个DoublyLinkedList中，所以当用户单击 Previous 按钮或 Next 按钮时，您可以轻松地来回导航。

Answer 2

我将文件行重构为这样：

q1 = What is his name? | John | David
q2 = How old is him? | 24 | 27

这样，每个问题信息都在一行中，更容易解析。您只需将它作为属性文件加载，q1 和 q2 将是键，= 之后的将是值。之后，将其拆分为 | 或您决定使用的任何值。

我将您的代码重构为如下所示：

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;

public class NewJFrame extends javax.swing.JFrame {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private Properties props = new Properties();
    private List<Question> questionList = new ArrayList<>();
    private int currentQuestionIndex = -1;

    private class Question {
        private String question;
        private String answer1;
        private String answer2;

        @Override
        public String toString() {
            return "Question [question=" + question + ", answer1=" + answer1 + ", answer2=" + answer2 + "]";
        }

        public Question(String question, String answer1, String answer2) {
            this.question = question;
            this.answer1 = answer1;
            this.answer2 = answer2;
        }

        public String getQuestion() {
            return question;
        }

        public String getAnswer1() {
            return answer1;
        }

        public String getAnswer2() {
            return answer2;
        }

    }

    public void showNextQuestion() {
        currentQuestionIndex++;
        if (currentQuestionIndex >= questionList.size()) {
            jTextArea1.setText("No more questions available.");
            return;
        }
        jTextArea1.setText("");
        Question currentQuestion = questionList.get(currentQuestionIndex);
        String newLine = "\n";
        jTextArea1.append(currentQuestion.getQuestion() + newLine);
        jTextArea1.append("A. " + currentQuestion.getAnswer1() + newLine);
        jTextArea1.append("B. " + currentQuestion.getAnswer2());
    }

    public NewJFrame() throws IOException {
        initComponents();
        setLocationRelativeTo(null);
        pack();

        Path path = Paths.get("/home/xxx/Desktop/englishQuestion.txt");
        props.load(Files.newInputStream(path));

        props.forEach((key, value) -> {
            String v = (String) value;
            System.out.println(v);
            String[] token = v.split("\|");
            String question = token[0];
            String answer1 = token[1];
            String answer2 = token[2];
            Question q = new Question(question, answer1, answer2);
            questionList.add(q);
        });

        showNextQuestion();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jButton1 = new javax.swing.JButton();
        textField1 = new java.awt.TextField();
        label1 = new java.awt.Label();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("Next");

        jButton1.addActionListener(e -> {
            showNextQuestion();
        });

        textField1.setName("\"\""); // NOI18N
        textField1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                textField1ActionPerformed(evt);
            }
        });

        label1.setText("Answer:");

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(javax.swing.GroupLayout.Alignment.TRAILING,
                        layout.createSequentialGroup().addGap(0, 0, Short.MAX_VALUE)
                                .addComponent(label1, javax.swing.GroupLayout.PREFERRED_SIZE,
                                        javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 53,
                                        javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 57,
                                        javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addGap(28, 28, 28))
                .addGroup(layout.createSequentialGroup()
                        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 421,
                                javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)));
        layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
                javax.swing.GroupLayout.Alignment.TRAILING,
                layout.createSequentialGroup().addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 206,
                                javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                .addComponent(label1, javax.swing.GroupLayout.PREFERRED_SIZE,
                                        javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 30,
                                        javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addComponent(jButton1))
                        .addContainerGap()));

        label1.getAccessibleContext().setAccessibleName("Answer: ");

        pack();
    }// </editor-fold>

    private void textField1ActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
    }

    /**
     * @param args
     *            the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        // <editor-fold defaultstate="collapsed" desc=" Look and feel setting code
        // (optional) ">
        /*
         * If Nimbus (introduced in Java SE 6) is not available, stay with the default
         * look and feel. For details see
         * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        // </editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    new NewJFrame().setVisible(true);
                } catch (IOException ex) {
                    Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea jTextArea1;
    private java.awt.Label label1;
    private java.awt.TextField textField1;
    // End of variables declaration
}

请注意，我使用 Properties 对象来加载所有键，然后对于每一行，我对其进行解析并创建一个 Question 对象并将其添加到 questionList。另外，请注意 jButton1.addActionListener(e -> { showNextQuestion(); });。调用 showNextQuestion();每次你想要下一个问题时的方法，在这种情况下，每次都单击“下一步”按钮。

我不确定你想用这个应用程序完成什么，目前还不清楚，但我只是简单地回答了你关于如何显示下一个问题的问题。

单击下一个按钮时显示下一个问题

Show next question when next button is clicked

java

swing

file

jframe