使用 JFileChooser 设置默认保存扩展名
我正在尝试使用 JFileChooser
保存文件.但是,我似乎遇到了一些麻烦.这是我的代码:
I'm trying to save a file using JFileChooser
. However, I seem to be having some trouble with it. Here's my code:
if (e.getSource() == saveMenu) {
JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
FileNameExtensionFilter xmlFilter = new FileNameExtensionFilter("xml files (*.xml)", "xml");
// add filters
chooser.addChoosableFileFilter(xmlFilter);
chooser.setFileFilter(xmlFilter);
int result = chooser.showSaveDialog(Simulation.this);
if (result == chooser.APPROVE_OPTION) {
writeToXML(chooser.getSelectedFile());
}
}
这并不强制文件具有 .xml
扩展名,因此我尝试使用以下代码强制文件以扩展名 .xml 保存
This doesn't force the file to have a .xml
extension, so I've tried to use the following code to force the file to be saved with the extension .xml
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter xmlWriter = null;
try {
xmlWriter = new XMLWriter(new OutputStreamWriter(
new FileOutputStream(f+".xml"), "UTF8"),
format);
但是,这样我不能阻止用户在 JFileChooser
中编写 xpto.xml
,如果他们这样做,文件将具有两个扩展名":它将是一个名为 xpto.xml.xml
However, with this I can't prevent the user from writing xpto.xml
in the JFileChooser
and if they do that, the file will have "two extensions": it will be a file named xpto.xml.xml
所以我的问题是:
- 如何让
JFileChooser
默认保存一个xml文件? - 如果用户插入了像 xpto.xml 这样的文件名,如何将其保存为 xpto.xml 而不是 xpto.xml.xml?
- How can I make the
JFileChooser
save an xml file by default? - If the user inserts a file name like xpto.xml, how can I save it as xpto.xml and not xpto.xml.xml?
推荐答案
如您所见,JFileChooser
不会在保存时强制执行 FileFilter
.它将在它显示的对话框中灰显现有的非 XML 文件,但仅此而已.要强制执行文件名,您必须完成所有工作.(这不仅仅是 JFileChooser 糟糕的问题 - 这是一个需要处理的复杂问题.您可能希望您的用户能够将他们的文件命名为 xml.xml.xml.xml
.)
As you've noticed, JFileChooser
doesn't enforce the FileFilter
on a save. It will grey-out the existing non-XML file in the dialog it displays, but that's it. To enforce the filename, you have to do all the work. (This isn't just a matter of JFileChooser sucking -- it's a complex problem to deal with. Your might want your users to be able to name their files xml.xml.xml.xml
.)
在您的情况下,我建议使用 FilenameUtils
来自 Commons IO:
In your case, I recommend using FilenameUtils
from Commons IO:
File file = chooser.getSelectedFile();
if (FilenameUtils.getExtension(file.getName()).equalsIgnoreCase("xml")) {
// filename is OK as-is
} else {
file = new File(file.toString() + ".xml"); // append .xml if "foo.jpg.xml" is OK
file = new File(file.getParentFile(), FilenameUtils.getBaseName(file.getName())+".xml"); // ALTERNATIVELY: remove the extension (if any) and replace it with ".xml"
}
如果您想在保存对话框中使用多种类型,还有一些建议:如何使用 JFileChooser 保存文件?
There's also some ideas for what to do if you want multiple types in the save dialog here: How to save file using JFileChooser?
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