java - JDialog 关闭时内存泄漏

Question

我正在开发一个 Java 应用程序，该应用程序由常规窗口 (JFrame) 和第一个菜单项调用的 JDialog 组成:

public class MainWindow {
    private JFrame frame;
    public MyDialog dialog;
    /* ... */
    private void initialize() {
         mnNew = new JMenuItem("New...");
         mnNew.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent arg0) {
             dialog = new MyDialog();
             }
         });
     }
}

并且MyDialog定义如下:

public class MyDialog extends JDialog {

    public MyDialog() {
        /* ... */
        JButton cancelButton = new JButton("Cancel");
        cancelButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                MyDialog.this.dispatchEvent(new WindowEvent(MyDialog.this,
                                            WindowEvent.WINDOW_CLOSING));
                MainWindow.window.matchMaker = null;
            }
        });
        /* ... */
        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        setVisible(true);
    }
}

一切正常，但我的任务管理器报告每次我打开然后关闭 MyDialog 时，程序都会消耗越来越多的内存。为什么？

Answer 1

• 原因是Top-Level Containers never will be GC'ed , Top-Level Containers are based on peer from Native OS

• 创建JDialog仅一次，通过 getContentPane.removeAll 重用它