[SalesForce] Email File Attachment type

I am trying to send an attachemnet in an email. I am able to do so the problem that i am having is that I am not able to get the original name and content type of the attachment.

Is there any way of extracting the same.

Public class Cls_SendEmail
{
    public String subject {get; set;}
    public String body {get; set;}
    public String to {get; set;}
    public String cc {get; set;}
    private Order__c order;
    private  EmailTemplate emailTemplatebody;
    public List<string> cc_addresses{get;set;}
    private EmailTemplate__c emailTemplateObj;

    public Attachment attachment {
             get {
                  if (attachment == null)
                      attachment = new Attachment();
                   return attachment;
                 }
             set;
      }

    // Constructor to populate instance of your object
    public MiC_Cls_SendEmail(ApexPages.StandardController controller) {

        this.order = (Order__c )controller.getRecord();
        order = [SELECT name, ContactEmail__c ,case__r.contact.name, case__r.contact.email, Qc_contact__r.email, Case__r.Case_Subject__C, Order_Type__c , Exchanged_Through__c FROM Order__c
             WHERE id = :ApexPages.CurrentPage().getParameters().get('id')];
    /*
        to =  order.Mic_case__r.contact.email;

        emailTemplatebody = [Select id, subject, body from EmailTemplate where 
                                            DeveloperName=:'ET_EmailInvoice'];                                  
   */
   try
   {
        emailTemplateObj = [Select Name, QC_Contact__r.email from EmailTemplate__c where Exchanged_Through__c =: order.Exchanged_Through__c
                            and Order_Type__c =: order.Order_Type__c]; 
        System.debug('emailTemplateObj = ' + emailTemplateObj.Name );
        to = emailTemplateObj.QC_Contact__r.email;
        emailTemplatebody = [Select id, subject, body from EmailTemplate where  DeveloperName=:emailTemplateObj.Name ];
        System.debug('emailTemplatebody  = ' + emailTemplatebody +  'emailTemplateObj.Name' +emailTemplateObj.Name);

        subject = emailTemplatebody.subject;        
        order.EmailBodyFromAgent__c = body;     
        cc_addresses = new List<string>();   
        body =  emailTemplatebody.body;   

        System.debug('Subject = ' +subject + 'body = ' + body);
     order.case__r.contact.name);  
     }
     catch(CalloutException e)
     {
         ApexPages.Message msg = new ApexPages.Message(ApexPages.Severity.INFO, 'No Email Template is Available' );
                       ApexPages.addMessage(msg);
     }

    }


    public pageReference send(){

            Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();  
            String[] toaddress = new String[]{};    
            toaddress.add(to);
            email.setToAddresses(toaddress); //Use SOQL to retrieve addresses in the address            
            email.setBccSender(true);

           if(cc.length() >0 && cc != null){
                        List<string> split_cc = new List<string>();
                        split_cc = cc.split(';');                        
                        for(string s: split_cc){
                            cc_addresses .add(s);
                         }
            }   

            email.setCcAddresses(cc_addresses ); 
            email.setTargetObjectId(order.case__r.contact.Id);
            email.setWhatId(order.Id); 
            emailTemplatebody.body = body;

            order.EmailBodyFromAgent__c = body; 
         // update emailTemplatebody;
            email.setTemplateId(emailTemplatebody.id);
            email.setSaveAsActivity(true);

        // Create the email attachment
        if( attachment != null)
        {
           Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
        //   efa.setFileName(attachment.name);
           efa.setFileName('file.docx');
           efa.setBody(attachment.body);
           efa.setContentType(attachment.ContentType);
           email.setFileAttachments(new Messaging.EmailFileAttachment[] {efa});
        }

            Messaging.SendEmailResult [] res = Messaging.SendEmail(new Messaging.SingleEmailMessage[] {email});      
            for ( Messaging.sendEmailResult result : res ) {
                   if ( !res[0].isSuccess () ) {
                       System.debug ( result  );
                   }
                   else{
                       ApexPages.Message msg = new ApexPages.Message(ApexPages.Severity.INFO, 'Email Sent Successfully' );
                       ApexPages.addMessage(msg);
                   }
               }  
            return null;

        }

}