You can save the pdf as attachemet not in the folder instead save it on database as follows,
 

public class attachPDFToAccount {
	
	private final Account a; //Account object
	
	//constructor
	public attachPDFToAccount(ApexPages.StandardController standardPageController) {
		a = (Account)standardPageController.getRecord(); //instantiate the Account object for the current record
	}
	
	//method called from the Visualforce's action attribute
	public PageReference attachPDF() {
		//generate and attach the PDF document
		PageReference pdfPage = Page.pdfDemo; //create a page reference to our pdfDemo Visualforce page, which was created from the post http://www.interactiveties.com/blog/2015/render-visualforce-pdf.php
		Blob pdfBlob = pdfPage.getContent(); //get the output of the page, as displayed to a user in a browser
		Attachment attach = new Attachment(parentId = a.Id, Name = 'pdfAttachmentDemo.pdf', body = pdfBlob); //create the attachment object
		insert attach; //insert the attachment
		//redirect the user
		PageReference pageWhereWeWantToGo = new ApexPages.StandardController(a).view(); //we want to redirect the User back to the Account detail page
		pageWhereWeWantToGo.setRedirect(true); //indicate that the redirect should be performed on the client side
		return pageWhereWeWantToGo; //send the User on their way
	}

}

 

<apex:page action="{!attachPDF}" extensions="attachPDFToAccount" standardController="Account">
<!--
	Created by: Greg Hacic
	Last Update: 7 August 2015 by Greg Hacic
	Questions?: greg@interactiveties.com
	
	Notes:
		- Visualforce page for creating a PDF file and attaching to Account
-->
	<apex:pageMessages></apex:pageMessages><!-- included for display of errors should they occur -->
	<apex:detail inlineEdit="true" relatedList="true"></apex:detail> <!-- included so Account detail information is visible when errors occur -->
</apex:page>

This will save the pdf as attachement. 

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