用IO流实现文件复制功能

public static void main(String[] args) throws Exception {
System.out.println("请输入读取文件（如文本,图片等）的路径：（如：D:\\Img.jpg）");
Scanner scannerIn = new Scanner(System.in);
String fileIn =scannerIn.nextLine();

System.out.println("请输入保存文件的路径。(如：E:\\abc.jpg)");
Scanner scannerout = new Scanner(System.in);
String fileOut =scannerout.nextLine();

FileInputStream fis = new FileInputStream(new File(fileIn));
FileOutputStream fos = new FileOutputStream(new File(fileOut));

byte[] bytes = new byte[1024*1024*4];//最大4M的缓冲区

while (fis.read(bytes)!=-1) {
fos.write(bytes);
}
fis.close();
fos.close();
System.out.println("文件保存成功，请在硬盘上查看"+fileOut);
}