2021-09-19 IO流(列出目录下所有内容-带层次)

import java.io.File;

public class Recursion3 {

    public static void main(String[] args) {
        File file = new File("H:\\Android");
        showDir(file, 0);
    }

    public static String getLevel(int level) {
        StringBuilder builder = new StringBuilder();
        builder.append("|--");
        for (int i = 0; i < level; i++) {
            builder.insert(0, "  ");
        }
        return builder.toString();
    }

    public static void showDir(File dir, int level) {
        System.out.println(getLevel(level) + dir.getName());
        level++;
        File[] files = dir.listFiles();
        for (int i = 0; i < files.length; i++) {
            if (files[i].isDirectory()) {
                showDir(files[i], level);
            } else {
                System.out.println(getLevel(level) + files[i]);
            }
        }
    }

}