java - 如果文件夹包含文件那么它在Java中显示Else忽略？

Question

如果文件夹包含文件，则仅在 Java 中显示该目录名称。我们怎样才能做到这一点。截至目前，我正在获取主文件夹和子文件夹名称。请查找快照以便更好地理解

public class GetChild {


    private static FileFilter onlyDirectories = new FileFilter() {
        @Override
        public boolean accept(File file) {
            return file.isDirectory();
        }
    };
     public static void main(String[] args) {
        File currentDir = new File("E:\\Folder"); // current directory
        displayDirectoryContents(currentDir);
    }

    public static void displayDirectoryContents(File dir) {
        StringBuilder sb1 = new StringBuilder("");
       doDisplayDirectoryContents(dir, sb1);

    }

    private static void doDisplayDirectoryContents(File dir, StringBuilder sb1) {
        File[] files = dir.listFiles(onlyDirectories);
        for (File file : files) {
            try {
                System.out.println("file.getCanonicalPath()===>" + file.getCanonicalPath());
                doDisplayDirectoryContents(file, sb1);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
      }
}

Answer 1

您可以结合使用 FileFilter 和 File.listFiles() 来实现此目的。

FileFilter filter = new FileFilter() {
    @Override
    public boolean accept(File pathname) {
        return pathname.isFile();
    }
};
if (file.listFiles(filter).length > 0) {
    System.out.println("file.getCanonicalPath()===>" + file.getCanonicalPath());
else
    continue;