In Spring, “Autowiring by Name” means, if the name of a bean is same as the name of other bean property, auto wire it.
For example, if a “customer” bean exposes an “address” property, Spring will find the “address” bean in current container and wire it automatically. And if no matching found, just do nothing.
You can enable this feature via autowire="byName" like below :
<!-- customer has a property name "address" -->
<bean id="customer" class="com.mkyong.common.Customer" autowire="byName" />
<bean id="address" class="com.mkyong.common.Address" >
<property name="fulladdress" value="Block A 888, CA" />
</bean>
See a full example of Spring auto wiring by name.
1. Beans
Two beans, customer and address.
package com.mkyong.common;
public class Customer
{
private Address address;
//...
}
package com.mkyong.common;
public class Address
{
private String fulladdress;
//...
}
2. Spring Wiring
Normally, you wire the bean explicitly, via ref attribute like this :
<bean id="customer" class="com.mkyong.common.Customer" >
<property name="address" ref="address" />
</bean>
<bean id="address" class="com.mkyong.common.Address" >
<property name="fulladdress" value="Block A 888, CA" />
</bean>
Output
Customer [address=Address [fulladdress=Block A 888, CA]]
With autowire by name enabled, you do not need to declares the property tag anymore. As long as the “address” bean is same name as the property of “customer” bean, which is “address”, Spring will wire it automatically.
<bean id="customer" class="com.mkyong.common.Customer" autowire="byName" />
<bean id="address" class="com.mkyong.common.Address" >
<property name="fulladdress" value="Block A 888, CA" />
</bean>
Output
Customer [address=Address [fulladdress=Block A 888, CA]]
See another example, this time, the wiring will failed, caused the bean “addressABC” is not match the property name of bean “customer”.
<bean id="customer" class="com.mkyong.common.Customer" autowire="byName" />
<bean id="addressABC" class="com.mkyong.common.Address" >
<property name="fulladdress" value="Block A 888, CA" />
</bean>
Output
Customer [address=null]
this is the best explanation of autowire tha i have ever seen.
Sir, could you please tell us Why or When should we use autowiring by name?
beautiful Explanation
Thank you very much, sir…
best explanation of autowire..
thanks buddy
autowired best explained…. thank u
good example
The App.javav class should be
package com.mkyong.common;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext(“SpringBeans.xml”);
Address address = (Address) context.getBean(“address”);
System.out.println(“Address : “+ address.getFulladdress());
}
}
Hi,
Nice Tut.
i have a doubt.
Should Customer class contain a setter method for Address? Is it must right? (when we are autowiring byName)
I think we should have a setter method for address in Customer class, without it i am getting Customer [address=null] as output