Getting NumberFormatException while getting the value in JSP using JSTL - spring

Question

I am working on Spring/Hibernate sample web application. Actually, I am trying to load the employees from database. In this case, while getting the data from database for both employee and address tables i am getting the NumberFormat exception.
Following is the code i am working on,
JSP Code:
<c:if test="${!empty employeeList}">
<table class="data">
<c:forEach items="${employeeList}" var="emp">
<tr>
<td><c:out value="${emp.firstname}" /></td>
<td><c:out value="${emp.lastname}" /></td>
<td><c:out value="${emp.email}" /></td>
<td>Edit</td>
<td>Delete</td>
</tr>
</c:forEach>
Controller Code:
#RequestMapping(value = "/", method = RequestMethod.GET)
public String listEmployees(ModelMap map)
{
map.addAttribute("employeeList", employeeManager.getAllEmployees());
return "editEmployeeList";
}
Service Layer Code:
#Override
#Transactional
public List<EmployeeEnitity> getAllEmployees() {
return employeeDAO.getAllEmployees();
}
public List<EmployeeEntity> getAllEmployees() {
return this.sessionFactory.getCurrentSession().createQuery("select ee.firstname,ee.lastname,addr.email from " +
"com.howtodoinjava.entity.EmployeeEntity ee, com.howtodoinjava.entity.AddressEntity addr where ee.id=addr.id").list();
}
Please help me to resolve this exception

Answer 1

The return type of session.createQuery(String).list() in your service method getAllEmployees is List<Object[]>, it is not List<Employee>
In controller you are adding this List<Object[]> to your model at this line:
map.addAttribute("employeeList",employeeList);
Now in JSP you are trying to access the model object in JSTL forEach loop:
<c:forEach items="${employeeList}" var="emp">
As employeeList represents List<Object[]>, the variable emp represents Object[], it is not Employee. Now using dot (.) operator on variable emp means you are trying to access an element at a particular index position. For example:
emp.0 --> is same as emp[0]
emp.1 --> is same as emp[1]
emp.indexPosition --> is same as emp[indexPosition]
So when you say emp.firstName, then the firstName is converted to integer, as firstName is not an integer you are getting NumberFormatException