java inputstream长度,获取Java中InputStream的大小

I am trying to encrypt an InputStream which I am getting from FileItem.getInputStream(); and I want to know the encrypted stream's length.

If it would be a simple FileInputStream, I could have tried File#length() or FileInputStream#getChennal().size() though not sure even those would have given me exactly what I want, but, in this case what I have is an InputStream (the encrypted one) and I want to find length of the same, I tried searching on Internet but there I could not find any efficient solution to that.

Please help

解决方案

You can output whats in InputStream and get the length

ObjA = new ObjA;

while( more message to read ){

ObjA = inputStreamObj.read();

}

System.out.println(ObjA.length());