Javaweb file upload Download, use FileUpload component

First, the introduction of JAR package

1. Commons-fileupload-1.2.1.jar

2. Commons-io-1.4.jar

Second, file upload

1. HTML code

1 <formname= "Upload_test"Action= "${pagecontext.request.contextpath}/fileservlet?method=upload"Method= "POST"enctype= "Multipart/form-data">2User name:<inputtype= "text"name= "UserName" > <BR>3File:<inputtype= "File"name= "FileName" > <BR>4           <inputtype= "Submit"value= "Upload" >5       </form>

2. Java code

1     Private voidUpload (httpservletrequest request, httpservletresponse response)2     throwsservletexception, IOException {3String URI =NULL;4         Try {5             //File Upload Factory6Fileitemfactory factory =Newdiskfileitemfactory ();7             //File Upload core tool class8Servletfileupload upload =Newservletfileupload (factory);9             /*** * * Set Size LIMIT Parameters * * * **/Ten             //Single File size limit OneUpload.setfilesizemax (10*1024*1024); A             //total File size limit -Upload.setsizemax (50*1024*1024); -             //encoding and processing of Chinese files theUpload.setheaderencoding ("UTF-8"); -             //Judging: Whether the current form is a file upload form -             if(upload.ismultipartcontent (Request)) { -                 //convert the request data to a Fileitem object, and then encapsulate it in a collection +list<fileitem> list =upload.parserequest (request); -                 //traverse: Get each uploaded data +                  for(Fileitem item:list) { A                     //Judging type (true: Normal form | | false: Upload form) at                     if(Item.isformfield ()) { -                         //Get name -String name =item.getfieldname (); -                         //Get Value -String value =item.getstring (); -                         //Print Content inSystem.out.println ("Name:" + name + "\tvalue:" +value); -}Else { to                         /*** * * Upload FORM * * * **/ +                         //Get file name -String name =item.getname (); the                         //----deal with the name of uploading file names---- *                         //gets a 36-bit UUID string $String ID =Uuid.randomuuid (). toString ();Panax Notoginseng                         //Stitching file name -Name = ID + "#" +name; the                         //Get upload directory +String basepath = Getservletcontext (). Getrealpath ("Upload"); ASystem.out.println ("BasePath:" +basepath); the                         //Create a File object to upload +File File =NewFile (basepath, name); -                         //Upload $ item.write (file); $                         //Delete temporary files that are generated when the component runs - Item.delete (); -                     } the                 } -}Else {WuyiSystem.out.println ("Not upload form"); the             } -              WuURI = "/success.jsp"; -}Catch(fileuploadexception e) { About e.printstacktrace (); $URI = "/error/error.jsp"; -}Catch(Exception e) { - e.printstacktrace (); -URI = "/error/error.jsp"; A}finally { + Request.getrequestdispatcher (URI). Forward (request, response); the         } -}

Third, File download

------------------digging pits to fill----------

Javaweb file upload Download, use FileUpload component