email - Java Mail with Attachment-Attachment file location not found -

my code sending email without attachment works fine. when try send email wth attachment, getting error message

'c:\temp\test.txt (the system cannot find file specified)' code below: '

  package com.abe.test;     import java.util.properties;     import javax.mail.*;     import javax.activation.*;     import javax.mail.internet.internetaddress; import javax.mail.internet.mimebodypart; import javax.mail.internet.mimemessage; import javax.mail.internet.mimemultipart;   public class testjavamail {      /**      * @param args      */      public static void main(string[] args) {          final string username = "from@gmail.com";         final string password = "xxxx";          properties props = new properties();         props.put("mail.smtp.auth", true);         props.put("mail.smtp.starttls.enable", true);         props.put("mail.smtp.host", "smtp.gmail.com");         props.put("mail.smtp.port", "587");          session session = session.getinstance(props,                 new javax.mail.authenticator() {                     protected passwordauthentication getpasswordauthentication() {                         return new passwordauthentication(username, password);                     }                 });          try {              message message = new mimemessage(session);             message.setfrom(new internetaddress("from@gmail.com"));             message.setrecipients(message.recipienttype.to,                     internetaddress.parse("to@gmail.com"));             message.setsubject("testing subject 1");             message.settext("pfa");             mimebodypart messagebodypart = new mimebodypart();              multipart multipart = new mimemultipart();              messagebodypart = new mimebodypart();              string file = "c:\\temp";             string filename = "test.txt";             datasource source = new filedatasource(file);              messagebodypart.setdatahandler(new datahandler(source));             messagebodypart.setfilename(filename);             multipart.addbodypart(messagebodypart);              message.setcontent(multipart);              system.out.println("sending");              transport.send(message);              system.out.println("done");          } catch (messagingexception e) {             e.printstacktrace();         }       }     } 

do need set classpath or else file attachment working?

thanks