java - 如何在每次创建新文件时增加文件名中的数字？

Question

您好，我目前正在用 Java 编写一个方法，我正在尝试创建新文件，但我需要这些文件不是同名的，而是递增名称值，如下所示:

• /Users/Myself/Desktop/myFile0.xml
• /Users/Myself/Desktop/myFile1.xml
• /Users/Myself/Desktop/myFile2.xml
• /Users/Myself/Desktop/myFile3.xml

所以我尝试在代码中执行以下操作，但我不明白为什么当我在 foreach 循环中调用文件(创建一个新循环)时，数字不会增加？

public void pickFolder() throws Exception {

    chooserFolder.setDialogTitle("Specify your save location");
    chooserFolder.setDialogType(JFileChooser.SAVE_DIALOG);

    int numbers = 0;
    chooserFolder.setSelectedFile(new File("myFile" + numbers++ + ".xml"));
    chooserFolder.setFileFilter(new FileNameExtensionFilter("xml file", "xml"));

    int userSelection = chooserFolder.showSaveDialog(null);
    if (userSelection == JFileChooser.APPROVE_OPTION) {

        for (File file : files) {

            chooserFolder.setSelectedFile(new File(chooserFolder.getSelectedFile().getAbsolutePath()));


            fileToSave = chooserFolder.getSelectedFile();
            if (fileToSave.createNewFile()) {
                System.out.println("File is created!");
                fileToSave = chooserFolder.getSelectedFile();

            } else {
                JOptionPane.showMessageDialog(null, "File already exists.");
            }

            System.out.println("Save as file: " + fileToSave.getAbsolutePath());

        }

任何帮助将不胜感激，谢谢!

Answer 1

您的数字变量应该是静态的；

public static int numbers = 0;

public void pickFolder() throws Exception {

chooserFolder.setDialogTitle("Specify your save location");
chooserFolder.setDialogType(JFileChooser.SAVE_DIALOG);

chooserFolder.setSelectedFile(new File("myFile" + numbers++ + ".xml"));
chooserFolder.setFileFilter(new FileNameExtensionFilter("xml file", "xml"));

int userSelection = chooserFolder.showSaveDialog(null);
if (userSelection == JFileChooser.APPROVE_OPTION) {

    for (File file : files) {

        chooserFolder.setSelectedFile(new File(chooserFolder.getSelectedFile().getAbsolutePath()));


        fileToSave = chooserFolder.getSelectedFile();
        if (fileToSave.createNewFile()) {
            System.out.println("File is created!");
            fileToSave = chooserFolder.getSelectedFile();

        } else {
            JOptionPane.showMessageDialog(null, "File already exists.");
        }

        System.out.println("Save as file: " + fileToSave.getAbsolutePath());

    }

这样，每当您调用 pickFolder() 时(无论您创建一个新实例还是使用同一实例)，您的 number 变量对于每个实例都保持相同。