问如何从DataInputStream java中只获取文件的前8个字节

EN

 public void getBinary() {

    try {


        // get the file as a DataInputStream
        DataInputStream input = new DataInputStream(new FileInputStream(file));

        try {

            // if files are avaliable countinue looping and get bytes / hex 
            while (input.available() > 0) {

                // build  a hex string from the bytes and change to uppercase 
                sb.append(Integer.toHexString(input.readByte()).toUpperCase());


                // need to get the first couple of (8) bytes 
            }



        } catch (IOException e) {
        }

        // print the hex out to command 

        //  System.out.println(sb.toString());

    } catch (FileNotFoundException e2) {
    } 

}