public void importData() { try { List<String> courses = Files.readAllLines(Paths.get("data/courses.txt"), StandardCharsets.UTF_8); List<String> scores = Files.readAllLines(Paths.get("data/scores.txt"), StandardCharsets.UTF_8); List<String> ids = Files.readAllLines(Paths.get("data/credits.txt"), StandardCharsets.UTF_8); List<String> semesters = Files.readAllLines(Paths.get("data/semesters.txt"), StandardCharsets.UTF_8); List<String> courseTypes = Files.readAllLines(Paths.get("data/types.txt"), StandardCharsets.UTF_8); this.courses.clear(); for (int i = 0; i < courses.size(); i++) { String course = courses.get(i); String id = ids.get(i); String score = scores.get(i); String semester = semesters.get(i); String courseType = courseTypes.get(i); addData(course,id,score,semester,courseType); Course student = new Course(course, score,id, semester, courseType); this.courses.add(student); //updateDisplay(); } //updateDisplay(); JOptionPane.showMessageDialog(null, "Data has been imported"); } catch (IOException e) { JOptionPane.showMessageDialog(null, "An error occurred importing data"); } }

这是一个 Java 代码段，主要是用来读取数据文件并将数据添加到程序中。首先，它读取五个文件，分别是课程名称、学分、成绩、学期和课程类型。然后，它将这些数据添加到程序中，并创建一个 Course 对象来表示每个课程。最后，它清空了先前的数据，并显示了一个消息框来通知用户数据已经导入。如果在导入数据时出现错误，它将显示另一个消息框来通知用户。

相关问题

public void importData() { List<String> files = Arrays.asList("courses.txt", "scores.txt", "credits.txt", "semesters.txt", "types.txt"); List<List<String>> fileContents = new ArrayList<>(); for (String file : files) { try (Stream<String> stream = Files.lines(Paths.get("F:\\ProgramData\\IdeaProjects\\BUPT-EBU6304G49-main\\SE0514\\src\\data\\" + file), StandardCharsets.UTF_8)) { fileContents.add(stream.collect(Collectors.toList())); } catch (IOException e) { JOptionPane.showMessageDialog(null, "An error occurred importing data"); return; } } this.courses.clear(); for (int i = 0; i < fileContents.get(0).size(); i++) { String course = fileContents.get(0).get(i); String score = fileContents.get(1).get(i); String credit = fileContents.get(2).get(i); String semester = fileContents.get(3).get(i); String courseType = fileContents.get(4).get(i); addData(course, credit, score, semester, courseType); this.courses.add(new Course(course, score, credit, semester, courseType)); } JOptionPane.showMessageDialog(null, "Data has been imported"); }代码经常返回异常，请优化这个代码，使数据可以正确从txt文件中读取

这段代码有几个问题需要优化：

1. 如果其中一个文件读取失败，整个方法就会返回并且数据无法正确导入，应该在每个文件读取失败后继续读取其他文件。

2. 在读取文件时，最好使用绝对路径，因为相对路径可能会因为不同的执行环境而不同。

3. 在解析文件内容时，最好检查文件内容的行数是否相等，否则会导致数据不匹配。

以下是优化后的代码：

public void importData() {
    List<String> files = Arrays.asList("courses.txt", "scores.txt", "credits.txt", "semesters.txt", "types.txt");
    List<List<String>> fileContents = new ArrayList<>();

    for (String file : files) {
        try (Stream<String> stream = Files.lines(Paths.get("F:/ProgramData/IdeaProjects/BUPT-EBU6304G49-main/SE0514/src/data/" + file), StandardCharsets.UTF_8)) {
            fileContents.add(stream.collect(Collectors.toList()));
        } catch (IOException e) {
            JOptionPane.showMessageDialog(null, "Failed to import data from file: " + file);
        }
    }

    if (fileContents.size() != 5) {
        JOptionPane.showMessageDialog(null, "Failed to import data");
        return;
    }

    // Check if each file has the same number of lines
    int numLines = fileContents.get(0).size();
    for (List<String> content : fileContents) {
        if (content.size() != numLines) {
            JOptionPane.showMessageDialog(null, "Failed to import data: files do not have the same number of lines");
            return;
        }
    }

    // Clear current data
    this.courses.clear();

    // Read data from files and add to list
    for (int i = 0; i < numLines; i++) {
        String course = fileContents.get(0).get(i);
        String score = fileContents.get(1).get(i);
        String credit = fileContents.get(2).get(i);
        String semester = fileContents.get(3).get(i);
        String courseType = fileContents.get(4).get(i);
        addData(course, credit, score, semester, courseType);
        this.courses.add(new Course(course, score, credit, semester, courseType));
    }

    JOptionPane.showMessageDialog(null, "Data has been imported");
}