Question

我发布了一个关于如何从文件中读取并从该文件中返回一个随机单词的问题，每个人都在告诉我使用“List words = new ArrayList（）;”我确实尝试使用它并且它不起作用！

我已经尝试了一切！我是java的新手，因为我还是学生！所以互联网是我的最后选择，教科书是没用的......

我想做的就是从该文件中返回一个随机字符串，然后将其用作猜测词

enter image description here

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

public final class Hangman extends JFrame implements ActionListener {
    int i = 0;
    static JPanel panel;
    static JPanel panel2;
    static JPanel panel3;
    static JPanel panel4;

    public Hangman() {
        JButton[] buttons = new JButton[26];

        panel = new JPanel(new GridLayout(0, 9));
        panel2 = new JPanel();
        panel3 = new JPanel();
        panel4 = new JPanel();

        JButton btnRestart = new JButton("Restart");
        btnRestart.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {

            }
        });

        JButton btnNewWord = new JButton("Add New Word");
        btnNewWord.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    FileWriter fw = new FileWriter("Words.txt", true);
                    PrintWriter pw = new PrintWriter(fw, true);

                    String word = JOptionPane
                            .showInputDialog("Please enter a word: ");

                    pw.println(word);
                    pw.close();
                } catch (IOException ie) {
                    System.out.println("Error Thrown" + ie.getMessage());
                }
            }
        });

        JButton btnHelp = new JButton("Help");
        btnHelp.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String message = "The word to guess is represented by a row of dashes, giving the number of letters and category of the word. \nIf the guessing player suggests a letter which occurs in the word, the other player writes it in all its correct positions. \nIf the suggested letter does not occur in the word, the other player draws one element of the hangman diagram as a tally mark."
                        + "\n"
                        + "\nThe game is over when:"
                        + "\nThe guessing player completes the word, or guesses the whole word correctly"
                        + "\nThe other player completes the diagram";
                JOptionPane.showMessageDialog(null, message, "Help",
                        JOptionPane.INFORMATION_MESSAGE);
            }
        });

        JButton btnExit = new JButton("Exit");
        btnExit.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
        JLabel lblWord = new JLabel();

        ImageIcon icon = new ImageIcon(
                "D:\\Varsity College\\Prog212Assign1_10-013803\\images\\Hangman1.jpg");
        JLabel label = new JLabel();
        label.setIcon(icon);
        String b[] = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K",
                "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
                "X", "Y", "Z" };
        for (i = 0; i < buttons.length; i++) {
            buttons[i] = new JButton(b[i]);

            panel.add(buttons[i]);
        }

        panel2.add(label);

        panel3.add(btnRestart);
        panel3.add(btnNewWord);
        panel3.add(btnHelp);
        panel3.add(btnExit);

        panel4.add(lblWord);
    }

    public void readWord() {
        try {
            BufferedReader reader = new BufferedReader(new FileReader(
                    "Words.txt"));
            String line = reader.readLine();
            List<String> words = new ArrayList<String>();
            while (line != null) {
                String[] wordsLine = line.split(" ");
                for (String word : wordsLine) {
                    words.add(word);
                }
                line = reader.readLine();
            }
            Random rand = new Random(System.currentTimeMillis());
            String randomWord = words.get(rand.nextInt(words.size()));
        } catch (Exception e) {
        }
    }

    public static void main(String[] args) {
        Hangman frame = new Hangman();
        Box mainPanel = Box.createVerticalBox();
        frame.setContentPane(mainPanel);
        mainPanel.add(panel, BorderLayout.NORTH);
        mainPanel.add(panel2);
        mainPanel.add(panel4);
        mainPanel.add(panel3);
        frame.pack();
        frame.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        throw new UnsupportedOperationException("Not supported yet.");
    }
}

Answer 1

Java中有两个名为List的类。有java.util.List和java.awt.List。确保你没有意外混合它们。我看到你正在导入java.awt.*，所以Java认为你想要java.awt.List，但是你想让java.util.List版本进行编译。最简单的方法是在问题陈述中完全限定List：

java.util.List<String> words = new ArrayList<String>();

Answer 2

你的问题在于

import java.awt.*;

java.awt包中包含一个名为List的类，就像java.util一样，但不是您想要的List。你试图导入它们导致干扰。之一：

删除import java.awt.*;并为您使用的特定类或
将列表参考限定为java.util.List<String>或
直接使用ArrayList<String>

Answer 3

您应该明确导入java.util.List

Answer 4

错误说明了一切：The type List is ambiguous

你打电话给两个不同的班级：

import java.util.ArrayList;

和

import java.awt.List;

由import java.awt.*;

调用

您必须为两个List实例使用相同的类。

例如：

import java.util.ArrayList;
import java.util.List;

或避免使用import java.awt.*;，而是使用

import java.awt.BorderLayout;
import java.awt.GridLayout;

或直接使用ArrayList<String>：

ArrayList<String> words = new ArrayList<String>();

“List <string> words = new ArrayList <string>（）;”不要编译</string> </string>

4 个答案: