File[] subFiles = src.listFiles(); // 拿到源文件夹里的文件和文件夹
for (File subfile : subFiles) {
if (subfile.isFile()) {
BufferedInputStream bis = new BufferedInputStream(
new FileInputStream(subfile));
BufferedOutputStream bos = new BufferedOutputStream(
new FileOutputStream(
new File(newdir, subfile.getName())));
int b;
while ((b = bis.read()) != -1) {
bos.write(b);