利用字节流复制文件

public class CopyFileByStream {
    public static void main(String[] args) {
     try {
        FileInputStream fileInputStream = new FileInputStream("learn.txt");
        FileOutputStream fileOutputStream = new FileOutputStream("learn22.txt",true);
        
        byte b [] = new byte[1024];
        int count = 0;
        long before = System.currentTimeMillis();
        while(fileInputStream.read(b)!= -1){
               fileOutputStream.write(b);
               count++;
        }
        //输入当前计算次数
        System.out.println(count);
        System.out.println(System.currentTimeMillis()-before);
        fileInputStream.close();
        fileOutputStream.close();
     
     } catch (Exception e) {
        e.printStackTrace();
    }
    }
}