Source of demand is this: a largefile belt  uploaded to server, server will parse this excel, then a one insertion into the database, the whole process should take a long time, so when the user clicks on the upload, you need to display a progress bar and according to the background of the amount of data received and processed timely progress update the progress bar.
Analysis: Background requires two components, uploadController.jsp used to receive and process the data, it will dynamically schedule information into the session, another component processController.jsp used to update the progress bar; when users click "Upload" after, form was submitted to the uploadController.jsp, while using js start a ajax request to processController.jsp, ajax progress percentage with access to update the progress bar displays the progress, and this process repeated once per second; this is the basic working principle of this case.
The question now is when the server receives data to know how the data received of the total number of data? If we start from scratch to write a file upload component, then this problem solved, the key is used many times we are mature components, such as apache commons fileupload; compare Fortunately, apache already thought of this problem, so the pre-left of the interface can be used to obtain the percentage of received data; therefore I use apache commons fileupload to receive upload files.

"System volume information." This file belt  is stored with the system restore backup information.
Completely remove method
1 run, type "gpedit.msc" / (Group Policy) program / Computer Configuration / Administrative Templates / System / System Restore / right turn off System Restore, double click to open it enabled.
  2, in the Run, type "gpedit.msc" / (Group Policy) program / Computer Configuration / Administrative Templates / windows components / windows Installer / On the right there is a "close the Create System Restore checkpoints," double-click to open it, select Enable.
  Using cacls command to give the current user full control permissions to delete the "System Volume Information" folder
  Command is as follows:
  cacls "c: \ System Volume Information" / g everyone: f
  These are granted to all users on the c drive System Volume Information folder Full Control permissions, you can delete the
  Detailed command at the command prompt: cacls /?
  Access methods
  How to get on the System Volume Information folder access
  Right-click My Computer / Properties / System Restore Debt / choose "Close all Restore", then delete the system Volume Information folder. Or My Computer / Any letter / Tools / Folder Options / View / Restore Defaults.