@required annotation usage. I tried giving this above setter method and tried to find the bean from context without setting this dependency. I got the object with the dependency is set null, my expectation was spring will throw some exception. Please guide me where I am doing wrong?
@Required to make it mandatory that the dependency has to be injected
Let us example: We need to use RequiredAnnotationPostProcessor which checks whether @Required
dependencies have been injected or not
public class BankService {
private CustomerService customerService;
private BillPaymentService billPaymentService;
@Required
public void setCustomerService(CustomerService customerService) {
this.customerService = customerService;
}
@Required
public void setBillPaymentService(BillPaymentService billPaymentService) {
this.billPaymentService = billPaymentService;
}
}
The configuration is like
<bean id="custService" class="xml.CustomerServiceImpl" />
<bean id="billingService" class="xml.BillPaymentServiceImpl" />
<bean id="bankService" class="xml.BankServiceImpl">
<property name="customerService" ref="custService" />
<property name="billPaymentService" ref="billingService" />
</bean>
<bean class=”o.s.beans.factory.annotation.RequiredAnnotationBeanPostProcessor" />
If we don't set both the properties we will get an error for the BankService configuration as both are @Required.
I hope this helps!!
Same anwer by bmt - just adding here what i did to verify.
package com.requiredAnnotation;
import org.springframework.beans.factory.annotation.Required;
public class BankService {
private CustomerService customerService;
private BillPaymentService billPaymentService;
@Required
public void setCustomerService(CustomerService customerService) {
this.customerService = customerService;
}
@Required
public void setBillPaymentService(BillPaymentService billPaymentService) {
this.billPaymentService = billPaymentService;
}
public BillPaymentService getBillPaymentService() {
return billPaymentService;
}
public CustomerService getCustomerService() {
return customerService;
}
}
package com.requiredAnnotation;
public class CustomerService {
}
package com.requiredAnnotation;
public class BillPaymentService {
}
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<bean id="customerService" class="com.requiredAnnotation.CustomerService" />
<bean id="billPaymentService" class="com.requiredAnnotation.BillPaymentService" />
<bean id="bankService" class="com.requiredAnnotation.BankService">
<property name="customerService" ref="customerService" />
<!-- <property name="billPaymentService" ref="billPaymentService" /> -->
</bean>
<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor" />
</beans>
package com.requiredAnnotation;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
ConfigurableApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:com/requiredAnnotation/beans-required.xml");
BankService bankService = applicationContext.getBean(BankService.class);
System.out.println("bankService got.");
System.out.println("getCustomerService - " + bankService.getCustomerService());
System.out.println("getBillPaymentService - " + bankService.getBillPaymentService());
}
}
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