例1:遞歸列舉出一個目錄下的所有文件 例2:將文件夾下所有.txt命名爲.sql

import java.io.File;

public class Main {
    public static void listDir(File file) {
        if (file.isDirectory()) {
            File[] results = file.listFiles();
            if (results != null) {
                for (int x = 0; x < results.length; x++) {
                    listDir(results[x]);
                }
            }
        }

        System.out.println(file);
    }

    public static void main(String[] args) {
        File file = new File("D:" + File.separator);
        listDir(file);
    }
}

例2

import java.util.List;

import java.io.File;

public class demo_04 {
    public static void listDir(File file) {
        if (file.isDirectory()) {
            File[] results = file.listFiles();
            if (results != null) {
                for (int x = 0; x < results.length; x++) {
                    listDir(results[x]);
                }
            }
        }

        if (file.getName().endsWith(".txt")) {
            // 得到新的完整路徑
            String newName = file.getAbsolutePath().substring(0, file.getAbsolutePath().indexOf(".txt")) + ".sql";
            file.renameTo(new File(newName));
        }
    }

    public static void main(String[] args) {
        String targetPath = "/Users/jianan/Documents/my_git/book/book_mysql_zgc";

        File file = new File(targetPath);
        listDir(file);
    }
}