byte[] bytes = "fsadf".getBytes();//byte数组
        try {
            OutputStream os = new FileOutputStream(new File("输出文件路径"));                       
            BufferedInputStream is = new BufferedInputStream(new ByteArrayInputStream(bytes));
            byte[] buf = new byte[1024];
            int len;
            while ((len = is.read(buf)) != -1) {
                os.write(buf, 0, len);
                os.flush();
            }
            is.close();
            os.close();
        } catch (IOException ex) {
            ex.printStackTrace(System.err);
        }