Use Apache-fileupload to process files uploading and uploading multiple files two (59)

One use Apache-fileupload to process file uploads

Framework: Refers to a code encapsulation of a business that is often handled by a user. Make it easy for users to call.

Current file Upload (frame) components:

Apache----FileUpload-

orialiy–cos–2008 ()-

jsp-smart-upload–200m.

Uploading Files with FileUpload:

You need to import a third-party package:

apache-fileupload.jar– File Upload core package.

apache-commons-io.jar– This package is a fileupload dependency package. It's also a toolkit.

Core class:

diskfileitemfactory– Set disk space to save temporary files. Just a class.

Servletfileupload-The core class of file uploads, this class receives the request, and resolves the reqeust.

Servletfileupload.parserequest (requdest)-list<fileitem>

First Step: Import Packages

Step two: Write a servlet to complete the Dopost method

/** * diskfileitemfactory Construction two parameters * First parameter: sizethreadhold-set cache (memory) How many bytes of data to save, default is 10K * If a file is not greater than 10K, directly using memory directly saved into a file. * If a file is larger than 10K, you need to save the file to the Temp directory first. * The second parameter File refers to the temporary directory location **/ Public classUp2servlet extends HttpServlet { Public voidDoPost (httpservletrequest req, HttpServletResponse resp) throws Servletexception, IOException {req.s Etcharacterencoding ("UTf-8"); //get the path to the projectString Path= Getservletcontext (). Getrealpath ("/up"); //The first step declares the Diskfileitemfactory factory class, which is used to set up a temporary directory on the disk that refers todiskfileitemfactory Disk=NewDiskfileitemfactory (1024x768*Ten,NewFile ("d:/a")); //Step Two: Declare servletfileupoload, receive the temp directory aboveServletfileupload up=Newservletfileupload (disk); //Step three: Parse request       Try{List<FileItem> list =up.parserequest (req); //If you have a fileFileitem File= list.Get(0); //get file name, with pathString FileName=File.getname (); FileName= Filename.substring (Filename.lastindexof ("\\")+1); //get the type of fileString FileType=File.getcontenttype (); //get the byte code of the fileInputStreaminch=File.getinputstream (); //declaring the output byte streamOutputStream out=NewFileOutputStream (path+"/"+fileName); //file Copy           byte[] B =New byte[1024x768]; intLen =0;  while((len=inch. Read (b))!=-1){               out. Write (b,0, Len); }            out. Close (); LongSize =File.getinputstream (). available (); //Delete the uploaded temporary filesFile.delete (); //Show DataResp.setcontenttype ("Text/html;charset=utf-8"); PrintWriter op=Resp.getwriter (); Op.print ("File Upload success <br/> filename:"+fileName); Op.print ("<br/> file type: ""+FileType); Op.print ("<br/> File Size (bytes)"+size); } Catch(Exception e) {e.printstacktrace (); }    }}

Two upload multiple files

First step: Modify the page's form to multiple input type= "file"

<form action="<c:url value= '/up3servlet '/>"Method="Post"Enctype="Multipart/form-data">File1:<input type="file"Name="txt"><br/>File2:<input type="file"Name="txt"><br/> <input type="Submit"/> </form>

Step Two: Traverse list<fileitem>

 Public classUp3servlet extends HttpServlet { Public voidDoPost (httpservletrequest request, httpservletresponse response) throws Servletexception, IOException { Request.setcharacterencoding ("UTF-8"); String Path= Getservletcontext (). Getrealpath ("/up"); //declaring diskDiskfileitemfactory disk =Newdiskfileitemfactory (); Disk.setsizethreshold (1024x768*1024x768); Disk.setrepository (NewFile ("d:/a")); //declaring a servlet that resolves requstServletfileupload up =Newservletfileupload (disk); Try{            //parsing Requstlist<fileitem> list =up.parserequest (Request); //declaring data for a file uploaded by a list<map> packagelist<map<string,string>> ups =NewArraylist<map<string,string>>();  for(Fileitem file:list) {Map<String,String> mm =NewHashmap<string, string>(); //Get file nameString FileName =File.getname (); FileName= Filename.substring (Filename.lastindexof ("\\")+1); String FileType=File.getcontenttype (); InputStreaminch=File.getinputstream (); intSize =inch. Available (); //using the tool classFileutils.copyinputstreamtofile (inch,NewFile (path+"/"+fileName)); Mm.put ("FileName", FileName); Mm.put ("FileType", FileType); Mm.put ("size",""+size);                Ups.add (mm);             File.delete (); } request.setattribute ("ups", UPS); //forwardingRequest.getrequestdispatcher ("/jsps/show.jsp"). Forward (request, response); }Catch(Exception e) {e.printstacktrace (); }    }}

Use Apache-fileupload to process files uploading and uploading multiple files two (59)