JPA - ExceptionInInitializerError when creating EntityManager


EntityFactoryManager(emf) is successfully received but error at emf.createEntityManager
Please see my code of fragment from my project.

public class Main { 
    final private static Properties EMAIL_PROPS; 
    final private static String EMAIL_FROM; 
    static { 
EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("tmpCLMSPU"); 
//       System.out.println("EMF: "+emf); //OUTPUT: EMF: org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl@ffa7e1 
        EntityManager emTemp = emf.createEntityManager(); 
TypedQuery<EmailSettings> emailSettings = emTemp.createNamedQuery("EmailSettings.findByName", EmailSettings.class).setMaxResults(1); 
        EmailSettings smtp, port, from; 
        smtp = emailSettings.setParameter("name", "SMTP").getSingleResult(); 
        port = emailSettings.setParameter("name", "Port").getSingleResult(); 
        from = emailSettings.setParameter("name", "EMAILFROM").getSingleResult(); 
        // Get system properties 
        EMAIL_PROPS = System.getProperties(); 
        // Setup mail server 
EMAIL_PROPS.put("", smtp.getValue()); 
EMAIL_PROPS.put("mail.smtp.port", port.getValue());  
        EMAIL_FROM = from.getValue(); 
   //Empty Constructor 
  public void Main() { 
public static void main(String[] args) { 
    new Main(); 

My project was was running successfully but All of sudden, it is showing following error:-

Caused by: javax.persistence.PersistenceException: java.lang.NullPointerException
                at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(

I am using Netbeans JAVA IDE for my project. I am very frustrated after lot of tries at my end to solve this problem. I tried following but FAILED:-
I ran my program again after each of following step but still Error is showing.
I check my database services. It is successfully connected. Connection is OK.
Restart Database server (SQL Server) services on Server.
Delete NetBeans configuration's Users directories.
Restart Server & Also, My client Computer.
Create a separate project & copy my original sources into it. I did the all configuration part of my project again i.e. adding Libraries, Setup Database Connections & Persistence Unit again.
However same database setup is working fine for other project. I found same problem on Internet:-
No proper solution is given on above link Because it is not NullPointerException. EntityFactoryMnager is retrieved successfully. Please see the attachments:- : an Entity : Main program to run
Persistence.xml.txt : File containing persistence information
Stacktrace.txt : complete stack trace after error is showing.

Have anyone idea to solve this problem?

Thanks In Advance,



> Restart Database server (SQL Server) services on Server.

This is the ObjectDB website and the forum focuses on using ObjectDB and not on other DBMS.

ObjectDB Support

Thanks for your Reply.

I'll take care your point & post only problem to this Forum which is related to objectdb.

This problem is SOLVED. For the sake of completion of this forum, I am giving solution here:-

I have an Entity named ShiftDetail in my project that has following error codes of line:-

     * any error occurred for getting this value from CLMS S/w then set it's
     * default value as 40 minutes. Minutes
    public static int SHIFT_SLOT; //Field SHIFTATTENDAFTERSLOT from AttendanceSettings table
    static {
        javax.persistence.EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("myDBPU");
        javax.persistence.EntityManager em = emf.createEntityManager();
        try {
            Object minutes = em.createNativeQuery("SELECT AttendanceSettings.Value FROM AttendanceSettings WHERE rtrim(LTRIM(Name))='SHIFTATTENDAFTERSLOT'")
            if (minutes != null && minutes instanceof String)
                SHIFT_SLOT = Integer.parseInt(minutes.toString());
                SHIFT_SLOT = 40; //Take default Time Slot as 40-minutes
        } catch (Exception ex) {
            SHIFT_SLOT = 40; //Take default Time Slot as 40-minutes


I should not use static field within an Entity & should not use EntityFactoryManager to initialize this field. I removed above lines from my source & I got solution... Thanks.