File Upload and file download

necessary prerequisites for uploading 1.1 files:

A, provide form form ,method must be post

b, the form form enctype must be multipart/form-data

C, provide input type= "file" class of the upload field

1.2enctype Properties

function: Notifies the server of the request body MIME type. (Request message header:content-type effect is consistent)

Optional values:

application/x-www-form-urlencoded ( default ):

Body: name=admin&password=123

Server fetch data: String name = Request.getparameter ("name");

Multipart/form-data:

The server gets the data: therequest.getparameter (String) method gets the specified form field character content, but the file upload form is no longer the character content, but the byte content, so the invalidation

File Upload: Parses the contents of each part of the request body.

        Request.setcharacterencoding ("UTF-8");                 = Request.getinputstream ();         int Len;         byte New byte [1024x768];                  while (len = Sis.read (b))! =-1) {            // output upload file contents            System.out.println (new String (b,0, Len));        }                Sis.close ();

File Upload and file download