jFileChooser程序继续运行

Question

该程序从文本文件中获取文本并将其放入名为textFile的字符串中。 我遇到的问题是在这个程序执行后程序继续运行，我需要手动杀死它来停止程序。我不明白为什么会这样。任何帮助将不胜感激。

代码：

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


  public class Main {
      public static void main(String[] args) {

    //selecting the txt file gui
    JFileChooser jFileChooser = new JFileChooser();
    int result = jFileChooser.showOpenDialog(new JFrame());
    java.io.File selectedFile = jFileChooser.getSelectedFile();

    if (result == JFileChooser.APPROVE_OPTION) {
        // System.out.println("Selected file: " + selectedFile.getAbsolutePath());
    } else {
        System.out.println("Error selecting file");
    }

    String textFile = "";

    try {
        //start filereader and buffered reader to read txt file that was selected
        FileReader fileReader = new FileReader(selectedFile);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        String line = bufferedReader.readLine();

        while(line != null) {
            textFile += line;
            line = bufferedReader.readLine();
        }
        bufferedReader.close();
        fileReader.close();

    } catch (Exception error) {
        System.out.println("Error selecting file\n");
        error.printStackTrace();
    }

    System.out.println(textFile);
 }
 }