Sending Email using java code

Question

I am using the following code to send an email from my java servlet but the problem is, when it is on its own it works fine but as soon as I combine it with some code to submit data into a postgres database it sometimes does not perform could it be because im missing some close statements??
//grades to submit grades starts here
                                                       String [] paramValues = req.getParameterValues("Mark");
                                                  for(int i=0; i<paramValues.length;i++)
                                                       String [] paramValues2 = req.getParameterValues("StudentExamNumber");
                                                            String Mark = paramValues;
                                                            String ExamNo = paramValues2[i];
                                                            //testing purposes
                                                            out.println("<tr><td>"+ExamNo+"</td>");
                                                            out.println("<td>"+Mark+"</td>");
                                                            try
                                                       st = conn.createStatement();
                                                       query = "SELECT StudentNo FROM STUDENTS"+WebCourse2+ " where ExamNo='"+ExamNo+"'";
                                                       rs = st.executeQuery(query);
                                                       if(rs !=null)
                                                                      while(rs.next())
                                                                           String StudentNo=rs.getString("StudentNo");
                                                                           //testing purposes
                                                                           //out.println("<td>"+StudentNo+"</td></tr>");
                                                                           here
                                                                           st4 = conn.createStatement();
                                                                 query4 = "select MAX(entryno) from STUDENTRESULTSFORCOURSE"+WebCourse2+" WHERE STUDENTNO='"+StudentNo+"'";
                                                                 rs4 = st4.executeQuery(query4);
                                                                 if(rs4 !=null)
                                                                                while(rs4.next())
                                                                                     EntryNo = rs4.getInt(1);
                                                                                }//end rs4 while
                                                                                rs4.close();
                                                                           }//end rs4 if
                                                                 out.println("<tr><td>EntryNo= "+EntryNo+"</td>");
                                                                           EntryNo = EntryNo + 1;
                                                                           out.println("<td>NewEntryNo= "+EntryNo+"</td></tr>");
                                                                           //Submitting grades to database/
                                                                 st3 = conn.createStatement();
                                                                 insert = "insert into STUDENTRESULTSFORCOURSE"+WebCourse2+" (StudentNo, CourseCode, AttemptNo, ExamMark, EntryNo, EnteredBy) values ('"+StudentNo+"', '"+WebCourse2+"', 1,'"+Mark+"',"+EntryNo+",'"+WebUsername2+"')";
                                                                 st3.executeUpdate(insert);
                                                                      }//end rs while
                                                                      rs.close();
                                                                 }//end rs if
                                                            }//end try
                                                            catch (SQLException e)
                                                                 System.out.println("Error: "+e.getMessage());
                                                       }//end for loop     
                                                       //code to submit grades ends here
                                                       //code used to send email starts here
                                                       String m_sHostName="localhost";
                                                  int m_iPort=25;
                                                       try
                                                            // Open port to server
                                                            smtpSocket = new Socket(m_sHostName, m_iPort);
                                                            os = new DataOutputStream(smtpSocket.getOutputStream());
                                                            is = new DataInputStream(smtpSocket.getInputStream());
                                                            if(smtpSocket != null && os != null && is != null)
                                                                 // Connection was made. Socket is ready for use.
                                                                 System.out.println("Connection was made. Socket is ready for use.");
                                                                 try
                                                                      // The email address that the server
                                                                      // you are using know user as.
                                                                      os.writeBytes("MAIL From: <[email protected]>\r\n");
                                                                      // Who the email is going to.
                                                                      os.writeBytes("RCPT To: <[email protected]>\r\n");
                                                                      //send a CC to:
                                                                      os.writeBytes("RCPT Cc: <[email protected]>\r\n");
                                                                      // add the message and the
                                                                      // header of the email to be sent out.
                                                                      os.writeBytes("DATA\r\n");
                                                                      os.writeBytes("X-Mailer: Via Java\r\n");
                                                                      os.writeBytes("From: "+WebUsername2+"<[email protected]>\r\n");
                                                                      os.writeBytes("To: Marie <[email protected]>\r\n");
                                                                      //Again if you want to send a CC then add this.
                                                                      os.writeBytes("Cc: ProfCuthbert <[email protected]>\r\n");
                                                                      String sMessage = "ELECTRONIC ENGINEERING EXAM COLLATION SYSTEM EMAIL\n\nThe results for the following course have been submitted by the following member of staff\n\nCOURSE: "+WebCourse2+"\n\nSUBMITTED BY: "+WebUsername2+" \n\nPLEASE LOCK COURSE NOW IN ORDER TO PREVENT ANY FURTHER SUBMISSIONS TO BE MADE BY USERS.";
                                                                      os.writeBytes("Subject: A SUBMISSION HAS BEEN MADE FOR COURSE "+WebCourse2+"\r\n");
                                                                      os.writeBytes(sMessage + "\r\n");
                                                                      os.writeBytes("\r\n.\r\n");
                                                                      os.writeBytes("QUIT\r\n");
                                                                      // Now send the email off and check the server reply.
                                                                      // Once an OK is reached you are complete.
                                                                      String responseline;
                                                                      //for testing purposes
                                                                      //out.println(responseline = is.readLine());
                                                                      while((responseline = is.readLine())!=null)
                                                                      //for testing purposes
                                                                      //out.println("responseline= "+responseline+"<br>");
                                                                      //out.println("responseline.indexOf(Ok)= "+responseline.indexOf("Ok"));
                                                                      if(responseline.indexOf("Ok") != -1)
                                                                      break;
                                                                      if(responseline.indexOf("Ok") == -1)
                                                                      confirm=1;
                                                                      if (confirm==1)
                                                                      out.println("<br>the marks have been submitted thank you");
                                                                      catch(Exception e)
                                                                      {  System.out.println("Cannot send email as an error occurred.");
                                                                           out.println("Cannot send email as an error occurred.");
                                                       catch(Exception e)
                                                       { System.out.println("Host " + m_sHostName + "unknown"); }
Does anyone know what the problem is??
thanks
tzaf

Answer 1

i close them later in the program. Ive made sure they are all closed I have a feeling that it could be coming from here....
//code used to send email starts here
                                                       String m_sHostName="localhost";
                                                  int m_iPort=25;
                                                       try
                                                            // Open port to server
                                                            smtpSocket = new Socket(m_sHostName, m_iPort);
                                                            os = new DataOutputStream(smtpSocket.getOutputStream());
                                                            is = new DataInputStream(smtpSocket.getInputStream());
                                                            if(smtpSocket != null && os != null && is != null)
                                                                 // Connection was made. Socket is ready for use.
                                                                 System.out.println("Connection was made. Socket is ready for use.");
                                                                 try
                                                                      // The email address that the server
                                                                      // you are using know user as.
                                                                      os.writeBytes("MAIL From: <email address>\r\n");
                                                                      // Who the email is going to.
                                                                      os.writeBytes("RCPT To: <email address>\r\n");
                                                                      //send a CC to:
                                                                      os.writeBytes("RCPT Cc: <email address>\r\n");
                                                                      // add the message and the
                                                                      // header of the email to be sent out.
                                                                      os.writeBytes("DATA\r\n");
                                                                      os.writeBytes("X-Mailer: Via Java\r\n");
                                                                      os.writeBytes("From: "+WebUsername2+"<email address>\r\n");
                                                                      os.writeBytes("To: hello<email address>\r\n");
                                                                      //Again if you want to send a CC then add this.
                                                                      os.writeBytes("Cc: hello <email address>\r\n");
                                                                      String sMessage = "ELECTRONIC ENGINEERING EXAM COLLATION SYSTEM EMAIL\n\nThe results for the following course have been submitted by the following member of staff\n\nCOURSE: "+WebCourse2+"\n\nSUBMITTED BY: "+WebUsername2+" \n\nPLEASE LOCK COURSE NOW IN ORDER TO PREVENT ANY FURTHER SUBMISSIONS TO BE MADE BY USERS.";
                                                                      os.writeBytes("Subject: A SUBMISSION HAS BEEN MADE FOR COURSE "+WebCourse2+"\r\n");
                                                                      os.writeBytes(sMessage + "\r\n");
                                                                      os.writeBytes("\r\n.\r\n");
                                                                      os.writeBytes("QUIT\r\n");
                                                                      // Now send the email off and check the server reply.
                                                                      // Once an OK is reached you are complete.
                                                                      String responseline;
                                                                      //for testing purposes
                                                                      //out.println(responseline = is.readLine());
                                                                      while((responseline = is.readLine())!=null)
                                                                      //for testing purposes
                                                                      //out.println("responseline= "+responseline+"<br>");
                                                                      //out.println("responseline.indexOf(Ok)= "+responseline.indexOf("Ok"));
                                                                      if(responseline.indexOf("Ok") != -1)
                                                                      break;
                                                                      if(responseline.indexOf("Ok") == -1)
                                                                      confirm=1;
                                                                      if (confirm==1)
                                                                      out.println("<br>the marks have been submitted thank you");
                                                                      catch(Exception e)
                                                                      {  System.out.println("Cannot send email as an error occurred.");
                                                                           out.println("Cannot send email as an error occurred.");
                                                       catch(Exception e)
                                                       { System.out.println("Host " + m_sHostName + "unknown"); }
                                                       //code used to send email ends here
do i need to close is and os?
thanks
tzaf