Hi, I am getting a null object from the get method of the hibernate session class.
Before presenting the problem, here is a quick background about my code and database schema.

I have an employee and a department class. Employee class has a field deptno which [nullable] foreign key and referring to the deptno of department table. Since deptno is a nullable a foreign key, I can always create an employee without any department assigned to him. After successful creation of an employee, I now want to assign him a department from the allocate department screen where I get employee information and a drop down list of available departments.

In the web layer, I am using jsf and I have a form bean named EmployeeFormBean. Instead of creating all the proerties in the EmployeeFormBean, I have simply put the object of Employee POJO having all the fields which are mapped to the datbase and a department object as well. The sole reason of doing this was everytime I want to save any information or get some data from the datase, I dont need to populate the formbean properties/ pojo properties again and again. {This might not be a good approach as it makes your middle layer and web layer tightly coupled. Point me in right direction if this is not a right way.}

Problem :- Having done all that, when i try to find any employee by primary key using get method of hibernate session object, I get the the employee pojo which has a null department pojo (if the emp is not assigned any department). As I have put the emp pojo in the EmployeeForm bean, in the jsp page i get employee's deptno by typing :--



Above code throws a null pointer exception as department is null.

Is there any way by which when I can configure the hibernate so that hibernateseesion.get method
class.

returns me a employee object which a department object (containing nothing) instead of a null department object.

One simple way could be -- having all the properties in the formbean and populating the form bean everytime we get a employee pojo which would be a tedious job.

Thanks in advance!!

sachin

Hi Sachin,

The problem here is that you are calling a method on an object which you already know MIGHT be null. Since you have designed the employee class to possibly have a null dept then you need to handle that possibility everytime you access your dept reference.

So you should never do something like getDepartmentPOJO().getDepartmentNo();

rather do
if(getDepartmentPOJO()!=null) {
//do dept stuff here
}

Hope that makes sense.

Cheers
Johnny