Java:在后台线程中读取文本文件的活动指示器

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JProgressBar;

public class FileReadThread extends Thread {
    private String filePath;
    private JProgressBar progressBar;

    public FileReadThread(String filePath, JProgressBar progressBar) {
        this.filePath = filePath;
        this.progressBar = progressBar;
    }

    @Override
    public void run() {
        try {
            BufferedReader reader = new BufferedReader(new FileReader(filePath));
            String line;
            int totalLines = 0;
            while ((line = reader.readLine()) != null) {
                // 处理每一行的内容
                // ...

                totalLines++;
                int progress = (int) ((double) totalLines / getTotalLines() * 100);
                progressBar.setValue(progress);
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private int getTotalLines() {
        // 计算总行数
        // ...

        return totalLines;
    }
}