Question

我遇到了一个我认为非常简单的程序的问题。我只想使用GUI，单击和按钮在文本文件中显示数据。我似乎很接近，但遇到了一个我不明白的问题。如果我按照它在这里的方式离开代码，我得到的错误是没有为第72行声明highScores（找不到符号）。但是如果我尝试声明highSchores，我得到错误“未报告的异常java.io.IOException;必须被捕或被宣布为“第69行被抛出。任何想法我做错了什么以及如何解决它？

create([_],N,J,K,J):- N>K.
create([X|Xs],N,L,K,J):- X==N , N1 is N + 1 , create(Xs,N1,[-1|L],K,J).
create([X|Xs],N,L,K,J):-N1 is N + 1 , create([X|Xs],N1,[0|L],K,J).

K is the size of the output list.
N is a counter .
L is the output.
X is the input list. 

?- create([1,2],1,[],5,N).
N = [0, 0, 0, 0, -1]

Answer 1

OpenFile（）方法抛出IOException，但它永远不会被捕获。

我做了一些修改：

可以将highScores声明为List（因此您不必提前提供行数）
发现了异常
换行符是＆＃34; \ n＆＃34;，不是＆＃34; / n＆＃34;

可以进行一些修改，但这应该有效：

import java.awt.Component;
import java.awt.Container;
import java.util.List;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;

public class TetrisScores extends JFrame {

    private JPanel contentPanel;
    private JButton btnSearch;
    private JButton btnLoad;
    private JButton btnSort;
    private JRadioButton firstSort;
    private JRadioButton secondSort;
    private JTextField searchInput;
    private JTextArea output;

    private List<String> highScores = new ArrayList<>();

    private void add(Container con, Component widget, int left, int top, int width, int height) // creates variables for
                                                                                                // bounds
    {
        widget.setBounds(left, top, width, height); // sets setBounds to created variables
        con.add(widget); // tells program container to use widget's bounds
    }

    TetrisScores() {
        contentPanel = (JPanel) getContentPane();
        contentPanel.setLayout(null);

        btnLoad = new JButton("Load File");
        add(contentPanel, btnLoad, 10, 10, 360, 40);

        searchInput = new JTextField("");
        add(contentPanel, searchInput, 10, 60, 240, 40);

        btnSearch = new JButton("Search");
        add(contentPanel, btnSearch, 260, 60, 110, 40);

        firstSort = new JRadioButton("Bubble Sort");
        add(contentPanel, firstSort, 20, 110, 110, 40);

        firstSort = new JRadioButton("Linear Sort");
        add(contentPanel, firstSort, 140, 110, 110, 40);

        btnSearch = new JButton("Sort");
        add(contentPanel, btnSearch, 260, 110, 110, 40);

        output = new JTextArea("");
        add(contentPanel, output, 10, 160, 360, 150);
        output.setEditable(false);

        setTitle("High Scores");
        setSize(500, 500);
        setLocation(new Point(150, 150));
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);

        btnLoad.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent add) {
                try {
                    OpenFile();
                    for (int j = 0; j < highScores.size(); j++) {
                        output.append(highScores.get(j) + "\n");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public void OpenFile() throws IOException {
        FileReader fr = new FileReader("tetrishighscore.txt");
        BufferedReader scoreReader = new BufferedReader(fr);

        String line;
        while((line = scoreReader.readLine()) != null) {
            highScores.add(line);
        }

        scoreReader.close();
    }

    public static void main(String[] args) {
        new TetrisScores();
    }
}

在JTextArea中打开和显示文件数据

1 个答案: