Java中文件与字节数组转换

注:来源于JavaEye

文件转化为字节数组:

http://www.javaeye.com/topic/304980

/**
     * 文件转化为字节数组
     *
     * @param file
     * @return
     */
    public static byte[] getBytesFromFile(File file) {
        byte[] ret = null;
        try {
            if (file == null) {
                // log.error("helper:the file is null!");
                return null;
            }
            FileInputStream in = new FileInputStream(file);
            ByteArrayOutputStream out = new ByteArrayOutputStream(4096);
            byte[] b = new byte[4096];
            int n;
            while ((n = in.read(b)) != -1) {
                out.write(b, 0, n);
            }
            in.close();
            out.close();
            ret = out.toByteArray();
        } catch (IOException e) {
            // log.error("helper:get bytes from file process error!");
            e.printStackTrace();
        }
        return ret;
    }

字节数组转化为文件

http://www.javaeye.com/topic/304982

/**
     * 把字节数组保存为一个文件
     *
     * @param b
     * @param outputFile
     * @return
     */
    public static File getFileFromBytes(byte[] b, String outputFile) {
        File ret = null;
        BufferedOutputStream stream = null;
        try {
            ret = new File(outputFile);
            FileOutputStream fstream = new FileOutputStream(ret);
            stream = new BufferedOutputStream(fstream);
            stream.write(b);
        } catch (Exception e) {
            // log.error("helper:get file from byte process error!");
            e.printStackTrace();
        } finally {
            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException e) {
                    // log.error("helper:get file from byte process error!");
                    e.printStackTrace();
                }
            }
        }
        return ret;
    }