IO操作总结

1，读取文件将文件转换为二进制流

        InputStream in = new FileInputStream("C:/test.png");
        byte[] photo = new byte[in.available()];
        in.read(photo);
        in.close();

2，写文件

        OutputStream out = new FileOutputStream("c:/copy.png");
        out.write(u.getPhoto());
        out.close();