java - 为什么小程序关闭服务器？

Question

我正在为我的项目实现一个使用 Java applet 的录音系统，但我在关闭 applet 时遇到一个问题，applet 关闭了服务器。有什么办法可以解决这个问题吗？我想在完成录制部分后继续我的项目，但在关闭小程序时录制后它也会停止服务器，所以我需要再次重新启动服务器。

有什么帮助或建议吗？

代码:-

 public class Main extends JPanel implements ActionListener {


    public Main() {
    setLayout(new BorderLayout());
    EmptyBorder eb = new EmptyBorder(5, 5, 5, 5);
    SoftBevelBorder sbb = new SoftBevelBorder(SoftBevelBorder.LOWERED);
    setBorder(new EmptyBorder(5, 5, 5, 5));

    JPanel p1 = new JPanel();
   // p1.setLayout(new BoxLayout(p1, BoxLayout.X_AXIS));
    JPanel p2 = new JPanel();
    p2.setBorder(sbb);
    p2.setLayout(new BoxLayout(p2, BoxLayout.X_AXIS));
    JPanel buttonsPanel = new JPanel();
    buttonsPanel.setBorder(new EmptyBorder(10, 0, 5, 0));
    radioGroup1 = new CheckboxGroup(); 
    radio1 = new Checkbox("Record  : ", radioGroup1,true); 
    p2.add(radio1);
    playB = addButton("Play", buttonsPanel, false);
    captB = addButton("Record", buttonsPanel, true);
    closeA = addButton("Close", buttonsPanel, true);
    p2.add(buttonsPanel);
    p1.add(p2);
    add(p1);

  }

  public void open() {
  }

  public void close() {
    if (playback.thread != null) {
      playB.doClick(0);
    }
    if (capture.thread != null) {
     captB.doClick(0);
    }
  }

  private JButton addButton(String name, JPanel p, boolean state) {
    JButton b = new JButton(name);
    b.addActionListener(this);
    b.setEnabled(state);
    p.add(b);
    return b;
  }

  public void actionPerformed(ActionEvent e) {

     Object obj = e.getSource();

    if (obj.equals(playB)) {
      if (playB.getText().startsWith("Play")) {
        playback.start();
        captB.setEnabled(false);
        playB.setText("Stop");
      } else {
        playback.stop();
        captB.setEnabled(true);
        playB.setText("Play");
      }
    } else if (obj.equals(captB)) {
      if (captB.getText().startsWith("Record")) {
        capture.start();
        playB.setEnabled(false);
        captB.setText("Stop");
      } else {
        capture.stop();
        playB.setEnabled(true);
      }

    }
    else if(obj.equals(closeA)) {
        System.exit(0);
    }

  }

  public class Playback implements Runnable {
    SourceDataLine line;
    Thread thread;
    public void start() {
      errStr = null;
      thread = new Thread(this);
      thread.setName("Playback");
      thread.start();
    }
    public void stop() {
      thread = null;
    }
    private void shutDown(String message) {
      if ((errStr = message) != null) {
        System.err.println(errStr);
      }
      if (thread != null) {
        thread = null;
        captB.setEnabled(true);
        playB.setText("Play");
      }
    }

    public void run() {


        AudioFormat format = getAudioFormat();
      try {
        audioInputStream = AudioSystem.getAudioInputStream(wavFile);
    } catch (UnsupportedAudioFileException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
      AudioInputStream playbackInputStream =   AudioSystem.getAudioInputStream(format,
          audioInputStream);

      if (playbackInputStream == null) {
        shutDown("Unable to convert stream of format " + audioInputStream + " to format " + format);
        return;
      }

      // get and open the source data line for playback.

      try {
        line = (SourceDataLine) AudioSystem.getLine(info);
        line.open(format, bufSize);



      } catch (LineUnavailableException ex) {
        shutDown("Unable to open the line: " + ex);
        return;
      }

      // play back the captured audio data

      int frameSizeInBytes = format.getFrameSize();
      int bufferLengthInFrames = line.getBufferSize() / 8;
      int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes;
      byte[] data = new byte[bufferLengthInBytes];
      int numBytesRead = 0;

      // start the source data line
      line.start();

      while (thread != null) {
        try {
          if ((numBytesRead = playbackInputStream.read(data)) == -1) {
            break;
          }
          int numBytesRemaining = numBytesRead;
          while (numBytesRemaining > 0) {
            numBytesRemaining -= line.write(data, 0, numBytesRemaining);
          }
        } catch (Exception e) {
          shutDown("Error during playback: " + e);
          break;
        }
      }
      // we reached the end of the stream.
      // let the data play out, then
      // stop and close the line.
      if (thread != null) {
        line.drain();
      }
      line.stop();
      line.close();
      line = null;
      shutDown(null);
    }

  } // End class Playback

  /**
   * Reads data from the input channel and writes to the output stream
   */
  class Capture implements Runnable {

    TargetDataLine line;

    Thread thread;

    public void start() {
      errStr = null;
      thread = new Thread(this);
      thread.setName("Capture");
      thread.start();
    }


    public void stop() {
      thread = null;
      line.close();
      //thread.stop();
    }

    private void shutDown(String message) {
      if ((errStr = message) != null && thread != null) {
        thread = null;
        playB.setEnabled(true);
        captB.setText("Record");
        System.err.println(errStr);
      }
    }

    public void run() {

      duration = 0;
      audioInputStream = null;

      Playback pb = new Playback();
      AudioFormat format = pb.getAudioFormat();
      DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);


      // get and open the target data line for capture.

      try {

        line = (TargetDataLine) AudioSystem.getLine(info);
       // line.open(format, line.getBufferSize());
        line.open(format);
        line.start();
        // saving audio file

        AudioInputStream ais = new AudioInputStream(line);

        // start recording
        AudioSystem.write(ais, fileType, wavFile);

      } catch (LineUnavailableException ex) {
        shutDown("Unable to open the line: " + ex);
        return;
      } catch (SecurityException ex) {
        shutDown(ex.toString());
        //JavaSound.showInfoDialog();
        return;
      } catch (Exception ex) {
        shutDown(ex.toString());
        return;
      }


      // we reached the end of the stream.
      // stop and close the line.
      line.stop();
      line.close();
      line = null;

      // stop and close the output stream
      try {
        out.flush();
        out.close();
      } catch (IOException ex) {
        ex.printStackTrace();
      }

      // load bytes into the audio input stream for playback

      byte audioBytes[] = out.toByteArray();
      ByteArrayInputStream bais = new ByteArrayInputStream(audioBytes);
      audioInputStream = new AudioInputStream(bais, format, audioBytes.length / frameSizeInBytes);

      long milliseconds = (long) ((audioInputStream.getFrameLength() * 1000) / format
          .getFrameRate());
      duration = milliseconds / 1000.0;

      try {
        audioInputStream.reset();
      } catch (Exception ex) {
        ex.printStackTrace();
        return;
      }

    }

  } // End class Capture

Answer 1

这段代码看起来不太好

else if(obj.equals(closeA)) {
        System.exit(0);
    }

这将导致 JVM 关闭。我还以为你只是想让小程序处于停止状态。