Question

我在动作监听器方法中编写程序的一部分时遇到了麻烦。这是我到目前为止的所有内容 - 任何帮助都会得到解释，并说明正在做什么。赋值需要使用JFileChooser。我有三个文件。一个包含名词，一个动词，一个包含一个故事，其中必须在随机选择后插入名词和动词。在故事文件中，＃被放置在名词必须去的地方，％放在动词必须去的地方。我需要取名词和动词并用它们替换符号。

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import java.util.*;

public class MadLibApp extends JFrame implements ActionListener
{
  JButton storyButton = new JButton("SELECT STORY FILE");
  JButton verbsButton = new JButton("SELECT VERBS FILE");
  JButton nounsButton = new JButton("SELECT NOUNS FILE");
  JFileChooser fileChooser = new JFileChooser();
  JTextField output = new JTextField(20);


  public static void main()
  {
     MadLibApp frame = new MadLibApp();
     frame.setBackground(Color.PINK);
     frame.setSize(300, 300);
     frame.setTitle("MAD LIB GAME");
     frame.createGUI();
     frame.setVisible(true);
  }

  public void createGUI()
  {
     setDefaultCloseOperation(EXIT_ON_CLOSE);
     Container window = getContentPane();
     window.setLayout(new FlowLayout());
     JPanel panel = new JPanel();
     panel.setSize(300,300);
     panel.setBackground(Color.PINK);
     window.add(panel);

     storyButton.addActionListener(this);
     verbsButton.addActionListener(this);
     nounsButton.addActionListener(this);
     JLabel outputLabel = new JLabel("Your Mad-Lib is: ");

     JButton button = new JButton("click to play");

     panel.add(storyButton);
     panel.add(verbsButton);
     panel.add(nounsButton);
     panel.add(outputLabel);
     panel.add(output);

  }

  public void actionPerformed(ActionEvent e)
  {
     Random selectRandomVerb = new Random();
     Random selectRandomNoun = new Random();

     int returnValue = fileChooser.showOpenDialog(null);
     if (returnValue == JFileChooser.APPROVE_OPTION) {
      File selectedFile = fileChooser.getSelectedFile();
      System.out.println(selectedFile.getName());
     }



     if (e.getSource().equals(verbsButton))
     {
        try 
        { 
        File verbsFile = fileChooser.getSelectedFile();

        if (verbsFile.exists())
        {
            Scanner verbsScanner = new Scanner(new FileInputStream(verbsFile));
            ArrayList<String> verbLines = new ArrayList<String>();
            String verbLine;
            while ((verbLine = verbsScanner.nextLine()) != null) {
                verbLines.add(verbLine);
            }
            int v = selectRandomVerb.nextInt(verbLines.size());
            String verb = verbLines.get(v);
        }
        else
        {
            JOptionPane.showMessageDialog(null, "That file does not exist.");
        }
         }
        catch (FileNotFoundException ev)
        {
        ev.printStackTrace();
       }
     }



     if (e.getSource().equals(nounsButton))
     {
        try
        {
         File nounsFile = fileChooser.getSelectedFile();

         if (nounsFile.exists())
         {
           Scanner nounsScanner = new Scanner(new FileInputStream(nounsFile));
           ArrayList<String> nounLines = new ArrayList<String>();
           String nounLine;
            while ((nounLine = nounsScanner.nextLine()) != null) {
                nounLines.add(nounLine);
            }
            int n = selectRandomNoun.nextInt(nounLines.size());
            String noun = nounLines.get(n);
         }
         else
         {
            JOptionPane.showMessageDialog(null, "That file does not exist.");
         }
        }
        catch(FileNotFoundException ev)
        {
         ev.printStackTrace();
        }
     }

     if (e.getSource().equals(storyButton))
     {
        File storyFile = fileChooser.getSelectedFile();
        try{
         if (storyFile.exists())
         {
            Scanner storyScanner = new Scanner(new FileInputStream(storyFile));
            ArrayList<String> storyArrayList = new ArrayList<String>();

            for (String element : storyArrayList) {
               if (storyScanner.nextLine() == "#")
               {

               }
            }

            for (String element : storyArrayList) {
               if (storyScanner.nextLine() == "%")
               {

               }
            }

            // output.setText();

         }
         else
         {
            JOptionPane.showMessageDialog(null, "That file does not exist.");
         }
         }
         catch(FileNotFoundException ev)
        {
         ev.printStackTrace();
         }
     }
  }



}

Answer 1

创建Scanner时，您应该传递FileInputStream来阅读文件，因为如果您通过System.in，Scanner将从控制台输入中读取。试试这个：

            try (Scanner sc = new Scanner(new FileInputStream(verbsFile));){

                ArrayList<String> lines = new ArrayList<String>();
                String line;
                while ((line = sc.nextLine()) != null) {
                    lines.add(line);
                }
                Random rd = new Random();
                int i = rd.nextInt(lines.size());
                String verb = lines.get(i); // this is a random verb from the verbsFile

            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }

仅当文件中的动词各自独立时才会起作用。

我看到你编辑了你的问题，以下是如何将更改写入storyFile：

     try (PrintWriter pw = new PrintWriter(new File("storyFile"));) {
        for (String line : storyArrayList) {
            if (line.equals("#")) {
                pw.append(noun);
            } else if (line.equals("%")) {
                pw.append(verb);
            } else {
                pw.append(line);
            }

            pw.write(System.lineSeparator());
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

在您阅读Scanner中的所有行并将storyFile和nouns变量设为全局后，您应该关闭verbs。您的代码中还有其他位置可以创建Scanners并将其保持打开状态。您的代码可以正常工作，但在EDT线程

上读取/写入文件并不是一个好习惯

Answer 2

我看不到

JFileChooser.APPROVE_OPTION

int returnValue = fileChooser.showOpenDialog(null);
if (returnValue == JFileChooser.APPROVE_OPTION) {
  File selectedFile = fileChooser.getSelectedFile();
  System.out.println(selectedFile.getName());
}

使用JFileChooser和扫描仪实现疯狂的lib游戏

2 个答案: