按层次打印指定目录下的文件和目录名称

import java.io.File;

public class Io01 {
    public static void main(String[] args) {
        File file = new File("d:/temp");
        getFiles(file, 0);

    }

    public static void getFiles(File file, int level) {
        if (file != null) {
            for (int i = 0; i < level; i++) {
                System.out.print("\t");
            }
            System.out.println(file.getName());
            if (file.isDirectory()) {
                level++;
                File[] files = file.listFiles();
                for (File f : files) {
                    getFiles(f, level);
                }
            }
        }
    }
}