Restrict the upload size, use COS to upload and download files 5 (63), and use cos to upload files

Restrict the upload size, use COS to upload and download files 5 (63), and use cos to upload files

I. Restrict upload size

1: Limit the total file size. For example, to upload 10 files, set the total upload size to 100 MB.

void	setSizeMax(long sizeMax) Sets the maximum allowed size of a complete request, as opposedsetFileSizeMax(long).

2: set the size of each file. If the size of each file is set to 10 MB.

 

void	setFileSizeMax(long fileSizeMax) Sets the maximum allowed size of a single uploaded file, as opposedgetSizeMax().

2. Use COS to upload files

 

Package cn. hx; import java. io. file; import java. io. IOException; import java. io. printWriter; import java. util. UUID; import javax. servlet. servletException; import javax. servlet. http. httpServlet; import javax. servlet. http. httpServletRequest; import javax. servlet. http. httpServletResponse; import com. oreilly. servlet. multipartRequest; import com. oreilly. servlet. multipart. defaultFileRenamePolicy; import com. oreilly. Servlet. multipart. FileRenamePolicy;/*** is a class in Cos. * MultipartRequest is the request packaging class. */Public class CosServlet extends HttpServlet {public void doPost (HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {// Step 1: declare the file storage directory String path = getServletContext (). getRealPath ("/up"); // Step 2: File Transfer // declare FileRenamePolicy rename = new DefaultFileRenamePolicy (); MultipartRequest req = new MultipartRequest (request, path, 1024*1024*100, "UTF-8", new MyRename (); // Step 3: Display Information, resp. setContentType ("text/html; charset = UTf-8"); PrintWriter out = resp. getWriter (); out. print ("file name 1:" + req. getOriginalFileName ("img1"); out. print ("<br/> new name:" + req. getFilesystemName ("img1"); out. print ("<br/> type 1:" + req. getContentType ("img1"); out. print ("<br/> size 1:" + req. getFile ("img1 "). length (); out. print ("<br/> note:" + req. getParameter ("desc1"); if (req. getContentType ("img1 "). contains ("image/") {out. print (" </img>") ;}} class MyRename implements FileRenamePolicy {public File rename (File file) {String fileName = file. getName (); String extName = fileName. substring (fileName. lastIndexOf (". "); String uuid = UUID. randomUUID (). toString (). replace ("-", ""); String newName = uuid + extName; // abc.jpg file = new File (file. getParent (), newName); return file ;}}

Download 3

That is, get can also be post.

Public VoidDoPost (HttpServletRequest req, HttpServletResponse resp)

ThrowsServletException, IOException {

Req. setCharacterEncoding ("UTF-8 ");

String name = req. getParameter ("name ");

// Step 1: Set the response type

Resp. setContentType ("application/force-download ");

// Second read the file

String path = getServletContext (). getRealPath ("/up/" + name );

InputStream in =NewFileInputStream (path );

// Set the Response Header

// Perform url encoding on the file name

Name = URLEncoder.Encode(Name, "UTF-8 ");

Resp. setHeader ("Content-Disposition", "attachment; filename =" + name );

Resp. setContentLength (in. available ());

// Step 3: Start file copy

OutputStream out = resp. getOutputStream ();

Byte[] B =New Byte[1024];

IntLen = 0;

While(Len = in. read (B ))! =-1 ){

Out. write (B, 0, len );

}

Out. close ();

In. close ();

}