Question

the client supposed to to upload a .ppt file , and the server supposed to save it and display it.

I did stored the (request.getContent() )in a DatainputStream object.

    DataInputStream pptFile = new DataInputStream(request.getInputStream());

But I cannot assign this type of variables ( DataInputStream) into an object from the library (org.apache.poi.hslf.usermodel.SlideShow).

 DataInputStream pptFile = new DataInputStream(request.getInputStream());
 SlideShow ppt = new SlideShow ( pptFile );

I need to use the pptFile as a FileInputStream variable, I know that I can convert from FileInputStream to DataInputStream easily, but How can I do the opposite? (Converting from DataInputStream to FileInputStream)

OR
At least Can I store the (request.getContent) inside a FileInputStream ??

Answer 1

DataInputStream is not an appropriate class for your requirements (read its Javadoc more carefully).

You can store the request in a ByteArrayInputStream and then provide that to the SlideShow object. This might use up a lot of memory (PPT files can get many megabytes in size), but get that working first. Then, investigate using a temporary file to save the upload instead of keeping it in memory.