java复制文件夹中的所有文件和文件夹到另一个文件夹中

public static void copyDir(String oldPath, String newPath) throws IOException {
        File file = new File(oldPath);
        String[] filePath = file.list();
        
        if (!(new File(newPath)).exists()) {
            (new File(newPath)).mkdir();
        }
        
        for (int i = 0; i < filePath.length; i++) {
            if ((new File(oldPath + "//" + filePath[i])).isDirectory()) {
                
//                File newDir = new File(path + "//" + filePath[i]);            
//                if (!newDir.exists()) {
//                    newDir.mkdir();
//                }
                copyDir(oldPath + "//"  + filePath[i], newPath  + "//" + filePath[i]);
            }
            
            if (new File(oldPath + "//" + filePath[i]).isFile()) {
           
                copyFile(oldPath + "//" + filePath[i], newPath + "//" + filePath[i]);
            }
            
        }
    }

public static void copyFile(String oldPath, String newPath) throws IOException {
        File oldFile = new File(oldPath);
        File file = new File(newPath);
        FileInputStream in = new FileInputStream(oldFile);
        FileOutputStream out = new FileOutputStream(file);;

        byte[] buffer=new byte[2097152];
        
        while((in.read(buffer)) != -1){
            out.write(buffer);
        }
    
        
    }

public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入源目录：");
        String sourcePath = sc.nextLine();
        System.out.println("请输入新目录：");
        String path = sc.nextLine();
        
        //String sourcePath = "D://aa";
        //String path = "D://bb";
        
        copyDir(sourcePath, path);
    }