从文件读取字节

//package com.nowjava;/* 来自 nowjava.com*/


import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;


public class Main {

    public static void main(String[] argv) throws Exception {

        File grammarFile = new File("Main.java");

        System.out.println(java.util.Arrays

                .toString(readBytesFromFile(grammarFile)));

    }
/** 时 代 J a v a 公 众 号 - N o w J a v  a . c o m 提供 **/

    /**

     * @param grammarFile

     * @return

     * @throws FileNotFoundException

     * @throws IOException

     */

    public static byte[] readBytesFromFile(File grammarFile)

            throws FileNotFoundException, IOException {

        byte[] oldBytes = null;

        if (grammarFile.exists()) {

            FileReader reader = new FileReader(grammarFile);

            ByteArrayOutputStream oldBytesStream = new ByteArrayOutputStream();