ContextListener is giving me error

[Priyanka Dande]

dear all,
again i am facing problem i am able to run Listener class also the ContextListener is initialised but it is giving me error on Tomcat 6.0 command prompt
Here is my Listener Class Sample.java i am able to compile the code but it is giving java.lang.nullpointer exception at runtime on Tomcat.exe
kindly help me to resolve this issue Is there is problem in my code

package servlet;
import java.io.*;
import java.io.FileInputStream;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
import javax.mail.internet.MimeMessage.*;                                                                                          
import javax.mail.internet.InternetAddress.*;
import java.util.*;
import java.io.IOException.*;
import java.util.Date;
import java.text.DateFormat;

import java.util.TimerTask;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import java.util.Date;
import java.text.SimpleDateFormat;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.*;

 
public class Sample implements ServletContextListener {
 
   
    public void contextInitialized(ServletContextEvent event) {
	 
     ServletContext sc = event.getServletContext();
     
               // create the timer and timer task objects
              System.out.println("TimerTask started");
               MyTimerTask task = new MyTimerTask();
               Timer timer = new Timer(true);
               // schedule the task to run hourly
              timer.scheduleAtFixedRate(task, 0, 100*60*60);
		        System.out.println("TimerTask started2");
                }
  
public void contextDestroyed(ServletContextEvent event){
 
System.out.println("Context Destroyed");
 }
 
 
class MyTimerTask extends TimerTask {

 SimpleDateFormat dfNew = new SimpleDateFormat("d-M-yyyy");
                        String dateStr = dfNew.format(new java.util.Date()); 
                        //out.print(dateStr);	
                        String ExpDt="";	
                        String NewEmail="";		
                        String DtHeadNewEmail="";						
                        String executeQuery;
						String executeUpdate;
                        String msg_bodyRtDT="";
						Connection con=null;
						Statement stmt,stmt1;
						ResultSet rst;
      
        public void run() {
                        
                    try
                    {
					                    System.out.println("hi");
                                        Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
                                        String url = "jdbc:oracle:thin:@plmpdb1c3:1521:CADPLMDB";
                                        con = DriverManager.getConnection(url,"root","root");
										System.out.println(con);
                                        stmt = con.createStatement();
                                        rst=stmt.executeQuery("select EXPECTEDRETDATE,EMAILID,DTHEADEMAIL from MatIssue where FLAG='0'");
                                        System.out.println(rst);
				while (rst.next()) {
                                                ExpDt=rst.getString(1); 
                                                NewEmail=rst.getString(2);
												DtHeadNewEmail=rst.getString(3);
												
                                   }
                    }
                    catch (Exception e){System.out.println(e);}  
                                try
                                {      
								                if(ExpDt.compareTo(dateStr)>0)
	                                                       {
                                                              System.out.println("Expected return date is greater than current date");
			                                               }
			                                    else if(ExpDt.compareTo(dateStr)==0)
			                                               {
                                                String subject = " Today is your due date kindly submit the material";
                                               
                                                   Properties props = new Properties();
                                                   props.put("mail.smtp.host", "128.9.41.19");
                                                   Session s = Session.getInstance(props,null);
                                               
                                                   MimeMessage message = new MimeMessage(s);
                                                     //MimeBodyPart mbp_file = new MimeBodyPart();
                                                    
                                                   
                                                   InternetAddress from = new InternetAddress("Test Mail");
                                                   message.setFrom(from);
                                                 
                                                   msg_bodyRtDT="<table><tr><td>Dear Sir/Madam ,<br><BR>Request you to kindly return the below material </td></tr>";
                msg_bodyRtDT=msg_bodyRtDT + "</table>";
                                                  
                                                 
                                               message.addRecipients(Message.RecipientType.TO,NewEmail);
                                                  message.addRecipients(Message.RecipientType.TO,DtHeadNewEmail);
                                                  message.addRecipients(Message.RecipientType.CC,"[e-mail]");
                                                  message.addRecipients(Message.RecipientType.CC,"[e-mail]");
                                                  message.setSubject(subject);                                                                      
                                                               
                                                 Multipart mp = new MimeMultipart();
                                     message.setContent(mp);
                                                                                    
                                                                                     
                                                // Message part 1 is text/html - add to multipart
                                                  MimeBodyPart m2 = new MimeBodyPart();
                                                  m2.setContent(msg_bodyRtDT, "text/html");
                                                  mp.addBodyPart(m2);
                                                Transport.send(message);        
                                                  
                                                         }
									
						     }
                                catch (Exception e)
                                {
                                                System.out.println(e);
                                }
							 try
							 {
							 stmt1.executeUpdate("Update MatIssue set Flag=1");    
                              }							 
							   catch (Exception e){System.out.println(e);}  
								
								
								
       }
    }
 
}

[Bear Bibeault]

Please show the error including the stack trace. Otherwise, we're just guessing.

[Priyanka Dande]

thanks the error is coming in Tomcat comand prompt window

2014-03-08 08:57:27 Commons Daemon procrun stdout initialized
TimerTask started
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
java.lang.NullPointerException
Context Destroyed

2014-03-08 11:03:18 Commons Daemon procrun stdout initialized
TimerTask started
TimerTask started2
oracle.jdbc.driver.T4CConnection@42238016
java.lang.NullPointerException
Context Destroyed

this is the error message

[Ulf Dittmer]

Print out the entire stack trace instead of just the error message. Then you'll know exactly in which line of code the exception occurred. You'd do that by "ex.printStrackTrace()".

[Priyanka Dande]

oracle.jdbc.driver.T4CConnection@3b19e583
oracle.jdbc.driver.OracleResultSetImpl@584a5c78
hi
hi
java.lang.NullPointerException
        at servlet.Sample$MyTimerTask.run(Sample.java:133)
        at java.util.TimerThread.mainLoop(Timer.java:512)
        at java.util.TimerThread.run(Timer.java:462)

[Ulf Dittmer]

I would guess that this points to the line that is #132 in the code above. There's only a single object that could be null, so that makes it pretty easy to find the problem :-)

[Priyanka Dande]

thanks for your prompt reply but i am not able to figure out the problem , can you tell me the error in my code please help

[Priyanka Dande]

The tomcat is also printing database values . where is the error i am not able to figure out, kindly help me to resolve this issue

Mar 8, 2014 12:25:10 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performanc
e in production environments was not found on the java.library.path: C:\Program
Files\Apache Software Foundation\Tomcat 6.0\bin;C:\Windows\Sun\Java\bin;C:\Windo
ws\system32;C:\Windows;C:\Program Files\Java\jdk1.6.0_33\bin;C:\Program Files\Ja
va\jre7\bin;C:\Program Files (x86)\Java\jdk1.5.0_08\bin;C:\Windows\system32;C:\W
indows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\P
rogram Files\Siemens\Teamcenter8.3\Visualization\Products\Mockup\ClearanceDB;C:\
Program Files\Java\jre7\bin;C:\php\;C:\php\ext\;;.
Mar 8, 2014 12:25:10 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Mar 8, 2014 12:25:10 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 612 ms
Mar 8, 2014 12:25:10 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Mar 8, 2014 12:25:10 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.39
Mar 8, 2014 12:25:10 PM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor host-manager.xml
Mar 8, 2014 12:25:11 PM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor manager.xml
Mar 8, 2014 12:25:11 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory docs
Mar 8, 2014 12:25:11 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory examples
Mar 8, 2014 12:25:11 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory Material-Issue
TimerTask started
TimerTask started2
hi
Mar 8, 2014 12:25:12 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory ROOT
Mar 8, 2014 12:25:12 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
Mar 8, 2014 12:25:12 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Mar 8, 2014 12:25:12 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/19  config=null
Mar 8, 2014 12:25:12 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 1257 ms
oracle.jdbc.driver.T4CConnection@5c74cb02
oracle.jdbc.driver.OracleResultSetImpl@29a7789c
hi
8-3-2014
[e-mail]
[e-mail]
hi
5-3-2014
[e-mail]
[e-mail]
java.lang.NullPointerException
        at servlet.Sample$MyTimerTask.run(Sample.java:136)
        at java.util.TimerThread.mainLoop(Timer.java:512)
        at java.util.TimerThread.run(Timer.java:462)

[Ulf Dittmer]

You seem to have changed your code, so that the problem is now in line 136. What happens in that line? Which object could be null (you know what a NullPointerException is and why it happens, right) ? Why could it be null?

[Priyanka Dande]

is it giving error on this line ??

stmt1.executeUpdate("Update MatIssue set Flag=1"); 

can you tell me where is my mistake?

[Ulf Dittmer]

That's probably the one. Think about it for a minute, and answer these question: 1) What is a NullPointerException, and why does it happen? 2) Which objects are used in this line of code? 3) Could any of them be null?

[Priyanka Dande]

thanks for your reply

A null pointer exception happens when you declare (create) a variable, but do not initialize it. An integer is zero by default,
but a non-number variable that doesn't have a value has the value null.Attempting to use a null object generates this exception,
because the program does not know what to do with that object

but i have already declared stmt1 in my code above in my code
and also executeUpdate


i have written the below line because i want to update the rows whose flag are 0 previously are set to 1 after sending the mail

stmt1.executeUpdate("Update MatIssue set Flag=1");  

[Ulf Dittmer]

A null pointer exception happens when you declare (create) a variable, but do not initialize it.

but i have already declared stmt1 in my code above in my code

Compare these two statements carefully, and you'll have your answer.

[Priyanka Dande]

thanks

should i initialise like below statement kindly guilde me i am not able to figure out my mistake .

Statement stmt,stmt1=null; 

i have try this also but still it is giving me error

Mar 8, 2014 1:03:55 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performanc
e in production environments was not found on the java.library.path: C:\Program
Files\Apache Software Foundation\Tomcat 6.0\bin;C:\Windows\Sun\Java\bin;C:\Windo
ws\system32;C:\Windows;C:\Program Files\Java\jdk1.6.0_33\bin;C:\Program Files\Ja
va\jre7\bin;C:\Program Files (x86)\Java\jdk1.5.0_08\bin;C:\Windows\system32;C:\W
indows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\P
rogram Files\Siemens\Teamcenter8.3\Visualization\Products\Mockup\ClearanceDB;C:\
Program Files\Java\jre7\bin;C:\php\;C:\php\ext\;;.
Mar 8, 2014 1:03:55 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 343 ms
Mar 8, 2014 1:03:55 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Mar 8, 2014 1:03:55 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.39
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor host-manager.xml
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor manager.xml
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory docs
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory examples
Mar 8, 2014 1:03:55 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory Material-Issue
TimerTask started
TimerTask started2
hi
Mar 8, 2014 1:03:56 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory ROOT
Mar 8, 2014 1:03:56 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
Mar 8, 2014 1:03:56 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Mar 8, 2014 1:03:56 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/13  config=null
Mar 8, 2014 1:03:56 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 803 ms
oracle.jdbc.driver.T4CConnection@5fc6e818
oracle.jdbc.driver.OracleResultSetImpl@3fde891b
hi
8-3-2014
[e-mail]
[e-mail]
hi
5-3-2014
[e-mail]
[e-mail]
java.lang.NullPointerException
        at servlet.Sample$MyTimerTask.run(Sample.java:136)
        at java.util.TimerThread.mainLoop(Timer.java:512)
        at java.util.TimerThread.run(Timer.java:462)

[Priyanka Dande]

My Sample.java code is

package servlet;
import java.io.*;
import java.io.FileInputStream;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
import javax.mail.internet.MimeMessage.*;                                                                                          
import javax.mail.internet.InternetAddress.*;
import java.util.*;
import java.io.IOException.*;
import java.util.Date;
import java.text.DateFormat;

import java.util.TimerTask;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import java.util.Date;
import java.text.SimpleDateFormat;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.*;

 
public class Sample implements ServletContextListener {
 
   
    public void contextInitialized(ServletContextEvent event) {
	 
     ServletContext sc = event.getServletContext();
     
               // create the timer and timer task objects
              System.out.println("TimerTask started");
               MyTimerTask task = new MyTimerTask();
               Timer timer = new Timer(true);
               // schedule the task to run hourly
              timer.scheduleAtFixedRate(new MyTimerTask(), 0, 100*60*60);
		        System.out.println("TimerTask started2");
                }
  
public void contextDestroyed(ServletContextEvent event){
 
System.out.println("Context Destroyed");
 }
 
 
class MyTimerTask extends TimerTask {

 SimpleDateFormat dfNew = new SimpleDateFormat("d-M-yyyy");
                        String dateStr = dfNew.format(new java.util.Date()); 
                        //out.print(dateStr);	
                        String ExpDt="";	
                        String NewEmail="";		
                        String DtHeadNewEmail="";						
                        String executeQuery;
						String executeUpdate;
                        String msg_bodyRtDT="";
						Connection con=null;
						Statement stmt,stmt1=null;
						ResultSet rst;
      
        public void run() {
                        
                    try
                    {
					                    System.out.println("hi");
                                        Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
                                        String url = "jdbc:oracle:thin:@plmpdb1c3:1521:CADPLMDB";
                                        con = DriverManager.getConnection(url,"erclc","erclc");
										System.out.println(con);
                                        stmt = con.createStatement();
                                        rst=stmt.executeQuery("select EXPECTEDRETDATE,EMAILID,DTHEADEMAIL from MatIssue where FLAG='0'");
                                        System.out.println(rst);
				while (rst.next()) {
				                                System.out.println("hi");
                                                ExpDt=rst.getString(1); 
												System.out.println(ExpDt);
                                                NewEmail=rst.getString(2);
												System.out.println(NewEmail);
												DtHeadNewEmail=rst.getString(3);
                                                System.out.println(DtHeadNewEmail);												
                                   }
                    }
                    catch (Exception e){e.printStackTrace();}  
                                try
                                {      
								                if(ExpDt.compareTo(dateStr)>0)
	                                                       {
                                                              System.out.println("Expected return date is greater than current date");
			                                               }
			                                    else if(ExpDt.compareTo(dateStr)==0)
			                                               {
                                                String subject = " Today is your due date kindly submit the material";
                                               
                                                   Properties props = new Properties();
                                                   props.put("mail.smtp.host", "128.9.31.19");
                                                   Session s = Session.getInstance(props,null);
                                               
                                                   MimeMessage message = new MimeMessage(s);
                                                     //MimeBodyPart mbp_file = new MimeBodyPart();
                                                    
                                                   
                                                   InternetAddress from = new InternetAddress("test mail ");
                                                   message.setFrom(from);
                                                 
                                                   msg_bodyRtDT="<table><tr><td>Dear Sir/Madam ,<br><BR>Request you to kindly return the below material </td></tr>";
                msg_bodyRtDT=msg_bodyRtDT + "</table>";
                                                  
                                                 
                                               message.addRecipients(Message.RecipientType.TO,NewEmail);
                                                  message.addRecipients(Message.RecipientType.TO,DtHeadNewEmail);
                                                  message.addRecipients(Message.RecipientType.CC,"[e-mail]");
                                                  message.addRecipients(Message.RecipientType.CC,"[e-mail]");
                                                  message.setSubject(subject);                                                                      
                                                               
                                                 Multipart mp = new MimeMultipart();
                                     message.setContent(mp);
                                                                                    
                                                                                     
                                                // Message part 1 is text/html - add to multipart
                                                  MimeBodyPart m2 = new MimeBodyPart();
                                                  m2.setContent(msg_bodyRtDT, "text/html");
                                                  mp.addBodyPart(m2);
                                                Transport.send(message);        
                                                  
                                                         }
									
						     }
                                catch (Exception e)
                                {
                                                e.printStackTrace();
                                }
							 try
							 {
							 stmt1.executeUpdate("Update MatIssue set FLAG='1'");    
                              }							 
							   catch (Exception e){e.printStackTrace();}  
								
								
								
       }
    }
 
}

[Ulf Dittmer]

Going by your previous post I thought you understood the difference between declaring an object, and initialising it, but apparently not. Post the lines of code where you are 1) declaring the object and 2) initialising the object.

[Priyanka Dande]

thanks for your guidance i understood instead of writing stmt1 i should put stmt

stmt.executeUpdate("Update MatIssue set FLAG='1'");

it get compiled it is not giving error on Tomcat command prompt but it is not sending mail to the user

oracle.jdbc.driver.T4CConnection@731de9b
oracle.jdbc.driver.OracleResultSetImpl@5b0d95cd
hi
oracle.jdbc.driver.T4CConnection@18f42160
oracle.jdbc.driver.OracleResultSetImpl@5e36d047
hi

(UD: deleted much more of this)

[Ulf Dittmer]

That is a different issue; please start a new thread and post the information that is relevant to sending mails.

[Ulf Dittmer]

Very important: You need to cut down the length of your posts to a minimum. There is no point in posting identical error messages 10 times, or output from loops that doesn't differ. Please edit your previous post and delete all that extraneous material. You can indicate if any of the messages occurred more than once, instead.

I'm confused. You said there was no error. But now there is an error?

[Priyanka Dande]

Sorry for the inconvinience cause
after i change the statement below

stmt1.executeUpdate("Update MatIssue set FLAG='1'"); 

to new statement

stmt.executeUpdate("Update MatIssue set FLAG='1'"); 

it get compiled but it is not generating proper output instead it is printing only upto this as

hi
oracle.jdbc.driver.T4CConnection@11742dfe
oracle.jdbc.driver.OracleResultSetImpl@627787a5
hi

means it is not going in the while loop now and not printing value and also not generating mail

and giving me output as

ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
plmpdb1c3:1521:CADPLMDB

        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java
:111)
        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java
:260)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:386)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:
440)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:164)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtensio
n.java:34)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:752)
        at java.sql.DriverManager.getConnection(DriverManager.java:582)
        at java.sql.DriverManager.getConnection(DriverManager.java:185)
        at servlet.Sample$MyTimerTask.run(Sample.java:70)
        at java.util.TimerThread.mainLoop(Timer.java:512)
        at java.util.TimerThread.run(Timer.java:462)
hi
oracle.jdbc.driver.T4CConnection@11742dfe
oracle.jdbc.driver.OracleResultSetImpl@627787a5
hi

kindly help i am not able to figure out my mistake or error in my code

[Ulf Dittmer]

Seems a DB-specific problem that you could ask about in the JDBC forum. If this was my problem I would convert this to a standalone desktop app that does all the DB and mail interaction, and only once I got that to work would I run it in a servlet environment. That would make testing so much easier and quicker, instead of having to start and restart web apps all the time.