You can make an update function that updates your jtable everytime you add/remove employee. Call this function after you add or remove an item in your table.
it might look something like this.
public void updateTable(JTable table){
DefaultTableModel model = (DefaultTableModel)table.getModel();
List<Employee> employees = employeeDao.getEmployees();
model.setRowCount(0); //empty your table
for(Employee employee:employees){
//add old and new data to table
model.addRow(new Object[]{employee.getFirstName(),employee.getLasName(),
employee.getDepartment()});
}
}
public void addEmployee(Employee employee){
//insert employee to your database
employeeDao.addEmployee(employee);
//update your table to include the inserted employee in table
updateTable(employeeJTable);
}