File转byte[]

File file = new File("文件路径");

FileInputStream inputStream=null;

ByteArrayOutputStream bytOutputStream=null;

try {
        //输入流
        inputStream = new FileInputStream(file);
            
        //输出流
        bytOutputStream= new ByteArrayOutputStream();

        byte[] b = new byte[1024];
            
        int n;

        while ((n = inputStream.read(b)) != -1){

                bytOutputStream.write(b, 0, n);
            
        }

        byte[] bytes = bytOutputStream.toByteArray();
            
     } catch (Exception e) {

            e.printStackTrace();

     }finally {

            try {

                inputStream.close();

                bytOutputStream.close();
               
            } catch (IOException e) {

                e.printStackTrace();

            }
      }     

原文地址：https://www.cnblogs.com/huyanlon/p/10334333.html