如何从Swing代码获取任何应用程序的根安装目录？

Question

I am designing a patch installer for an application. The first page (after welcome page) of the installer asks for the root directory of the installed application and a Browse button is provided for the user to choose the root directory. However, to facilitate the process I want the installer to intelligently find the root installer directory and set it as default in the text field rather than keeping it blank (As I have seen in many of the installers). What is the best way to accomplish the same?

private JButton getBrowseButton(JPanel panel) {
    final JButton browseBtn = new JButton(rm.getMessage("button.browse"));
    browseBtn.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent ae) {

            JFileChooser jfChooser = new JFileChooser(); 
            jfChooser.setCurrentDirectory(new java.io.File("."));
            jfChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            jfChooser.setAcceptAllFileFilterUsed(false);
            guiUtil.removeFilesOfTypeFromJFileChooser(jfChooser);     
            jfChooser.showOpenDialog(panel);
       }
    });
    return browseBtn;
}

I thought of using environment variables but the application does not set any environment variables which I could just System.getenv(String path) and get directly.

Any help would be appreciated.

Answer 1

Setting aside that it is probably a BAD IDEA to try to implement this yourself (see the Question comments) ....

There is no way that is going to work for all applications, because installation directories are a convention, not a requirement. Rather, it is necessary to implement this on a per-application / per-platform basis. Here are some ideas.

• Wire the installation directory path into the wrapper script used to launch the application, and pass it as a system property, command line parameter or environment variable.
• Store the installation directory path in an application configuration file.
• Infer the installation directory path from location of the wrapper script.
• Infer the installation directory path from the classpath.
• Store the installation directory path in the Windows registry, or similar.