public static void printHexByByteArray(String fileName) throws IOException{
		FileInputStream in=new FileInputStream(fileName);
		byte[] buf=new byte[8*1024];
		int bytes=0;
		int j=1;
		while((bytes=in.read(buf, 0, buf.length))!=-1){
			for(int i=0;i<bytes;i++){
				//为何下面的判断，会让双位数也加零
				if(buf[i]<=0xf){
					System.out.print("0");
				}
				System.out.print(Integer.toHexString(buf[i] & 0xff)+" ");
				if(j++%10==0){
					System.out.println();
				}
			}
		}
		in.close();
	}
}