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;
	}