java - 为什么 JFileChooser 会这样工作？

Question

大家好，好久不见了。所以我正在开发这个应用程序，它允许我制作和保存文档等等。这不是这个问题的重点。因此，在保存功能中，我决定使用 JFileChooser 来允许用户选择保存文件的位置。

现在我的 JFileChooser 可以正常启动，下面是代码:

 public void Save () {
        choicer.setCurrentDirectory(new java.io.File("C://"));
        choicer.setDialogTitle("Save Document");
        choicer.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        choicer.setAcceptAllFileFilterUsed(false);
        if (choicer.showSaveDialog(new JPanel()) == JFileChooser.APPROVE_OPTION) {
            dir = String.valueOf(choicer.getCurrentDirectory());
        }
        
        File f = new File(dir + "\\hi.txt");
    }

忽略 hi.txt 名称。我稍后会重点讨论。

现在我发现了两个问题。首先，我必须“深入”一个文件夹来保存我的文件。 说明:
假设我想将我的文件保存在用户的公共(public)目录中，我的目录如下所示:

C:\Users\Public
现在我的代码在文件参数中添加了 \hi.txt ，这不应该保存在公共(public)文件夹中吗？如果我在公开后只是保存在那里，我会得到一个异常(exception):

java.io.FileNotFoundException: C:\Users\Public (Access is denied)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileWriter.<init>(Unknown Source)
at Spreadr$TableMethods.Save(Spreadr.java:175)
at Spreadr.lambda$1(Spreadr.java:85)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.AbstractButton.doClick(Unknown Source)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

如果我公开打开一个文件夹，然后单击“保存”，我的目录现在看起来像:

C:\Users\Public\Downloads

然后，它不会保存在“下载”文件夹中，而是保存在“公共(public)用户”文件夹中。

这是我的第一个问题。我的第二个实际上是一个迷你问题类型的东西。我可以在“保存”菜单(JFileChooser 菜单)中命名我的文件吗？

Answer 1

您的代码调用 choicer.getCurrentDirectory() ，这将为您提供在 JFileChooser.DIRECTORIES_ONLY 模式下选择目录时所在目录的父目录。

您可能想要获取您选择的目录，您可以通过调用

choicer.getSelectedFile()