FileToByteArr.java

package com.baimes.utils;

import java.io.*;

/**
 * Created by Ds_Kidd on 2015/4/3 0003.
 * 将文件转换为byte数组,一般用于图片，视屏，及音频
 */
public class FileToByteArr {

    /**
     * 单元测试
     */
    public static  void main(String[] args){
       byte[] b = FileToByteArr.toByteArr("E:\\Users\\Desktop\\1.png");
        for(int i = 0;i < b.length;i++){
            byte a = b[i];
            System.out.println(a);
        }
    }

    /**
     * 只传入文件绝对路径
     * @param path 文件的绝对路径
     * @return 当文件存在时，返回byte[]，当文件不存在，返回一个长度为0的数组
     */
    public static byte[] toByteArr(String path) {
        try {
            File file = new File(path);
            byte[] buffer = null;
            FileInputStream fileInputStream = new FileInputStream(file);
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1000);
            try {
                byte[] b = new byte[1000];
                int n;
                while ((n = fileInputStream.read(b)) != -1) {
                    byteArrayOutputStream.write(b, 0, n);
                }
                buffer = byteArrayOutputStream.toByteArray();
            } catch (IOException e) {
                e.printStackTrace();
            }finally {
                try {
                    fileInputStream.close();
                    byteArrayOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return buffer;
        }catch (FileNotFoundException e){
            e.printStackTrace();
            byte[] bytes = new byte[0];
            return bytes;
        }

    }
}