How to Instantiate spring bean with in a method with runtime constructor arguments? - spring

Question

I need to instantiate a bean ( EmployeeSaver) with in a method with parameter coming in dynamically. I can't use constructor setter for these values are not populated at config time.
Sample code:
class MyEmployeeBean{
public void saveEmployeeDetail (Employee employee , EmployeeHistory hist ){
EmployeeDetail detail = hist.getDetail();
EmployeeSaver eSave = new EmployeeSaver(employee, detail)
saver.saveEmployee();
}
}
class EmployeeSaver {
private Employee empl;
private EmployeeDetail detail;
public EmployeeSaver(Employee emp, EmployeeDetail det){
empl = emp;
detail = det;
}
public void saveEmployee(){
// code to same the guy...
}
}
As MyEmployeeSaver class don't have default constructor so it's throwing runtime exception. I am unsable to use following config as employeeDetail is not know until I do hist.getDetail() !
<bean id="mySaverBean" class="come.saver.EmployeeSaver">
<constructor-arg name="empl" ref="employee" />
<constructor-arg name="hist" ref = "employeeHistory" />
</bean>
How to instantiate employeeSaverBean with constructor arguments?

Answer 1

You can't do this directly with Spring configuration, but using ApplicationContext.getBean(String beanName,Object...args) like described in this question.
MyEmployeeBean must implements ApplicationContextAware to access Spring's context
class MyEmployeeBean implements ApplicationContextAware {
ApplicationContext applicationContext;
void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
public void saveEmployeeDetail (Employee employee , EmployeeHistory hist ){
EmployeeDetail detail = hist.getDetail();
EmployeeSaver eSave = (EmployeeSaver)this.applicationContextnew.getBean("mySaverBean", employee, detail);
saver.saveEmployee();
}
}
and in beans.xml
<bean id="mySaverBean" class="come.saver.EmployeeSaver" scope="prototype" />
Remeber to addo scope="prototype" to let Spring create a new instance at every request.