Generate PDF attachment of opprtunity details

Pdf_of_Attachment

<apex:page standardController="Opportunity" extensions="Pdf_of_Attachment_Extension" renderAs="pdf"> 
    <apex:pageBlock >
        <apex:pageBlockSection columns="1" >    
                <apex:pageBlockSectionItem >Opportunity Name: {!Opportunity.Name}      </apex:pageBlockSectionItem>
                <apex:pageBlockSectionItem >CloseDate    : {!Opportunity.CloseDate}    </apex:pageBlockSectionItem>
                <apex:pageBlockSectionItem >StageName    : {!Opportunity.StageName}    </apex:pageBlockSectionItem>
                <apex:pageBlockSectionItem >Probability  : {!Opportunity.Probability}  </apex:pageBlockSectionItem> 
        </apex:pageBlockSection>
        <apex:repeat var="attachment" value="{!attachments}">
                  <apex:image url="/servlet/servlet.FileDownload?file={!attachment.Id}"/><br></br>
                </apex:repeat>
    </apex:pageBlock>
</apex:page>

Pdf_of_Attachment_Extension

public with sharing class Pdf_of_Attachment_Extension
{
    public String currentId {get;set;}  
    
    public Pdf_of_Attachment_Extension(ApexPages.StandardController controller)
    {
        currentId = ApexPages.currentPage().getParameters().get('id'); 
    }
    
    public List<Attachment> getattachments()
    {
        List<Attachment> attachmentList = [SELECT Id, Name, Body, ContentType 
                                        FROM Attachment 
                                        WHERE Parentid =: currentId];
        system.debug(attachmentList);
        return attachmentList;
    }
    
    public PageReference attachpdf(){    
        PageReference pdf = Page.Pdf_of_Attachment; 
        pdf.getParameters().put('id',currentId);
        Attachment attach = new Attachment();
            Blob body;
                try {
                    body = pdf.getContent();
                } catch (VisualforceException e) {
                    system.debug('Exception :'+e);
                }
        attach.Body = body;
        attach.ContentType = 'application/pdf';
        attach.Name = currentId +' Attachment';
        attach.IsPrivate = false;
        attach.ParentId = currentId ;
        try{
            insert attach;
        } catch (DMLException e) {
             system.debug(e);       
        }   
        PageReference pr = new pagereference('/'+currentId);
        return pr;
    }
}

Pdf_of_Attachment_Main

<apex:page standardController="Opportunity" extensions="Pdf_of_Attachment_Extension" action="{!attachpdf}">
</apex:page>