Autowiring in spring

Summary

• Autowiring is a mechanism in Spring that allows the framework to automatically detect and inject the dependent beans to the properties of the target bean without the need for explicit configuration.
• In simple words, when we apply autowiring, then Spring looks for the dependent beans in the container and automatically injects them into the target object.
• Benefits:
  • This can save a lot of time and effort, especially in large-scale applications where there are a large number of dependencies between objects.
• Drawbacks:
  • No control of the programmer.
  • It can’t be used for primitive and not recommended for string values.

Syntax

`

<bean class="com.autowire.demo.beans.Account" id="account">
    <property name="accountId" value="SV-101"/>
    <property name="balance" value="50000.0"/>
</bean>

<bean class="com.autowire.demo.beans.Address" id="address">
    <property name="houseNo" value="25"/>
    <property name="city" value="Bhopal"/>
</bean>

<bean class="com.autowire.demo.beans.Customer" id="customer" autowire="constructor">
    <constructor-arg index="0" value="Amit"/>
    <constructor-arg index="1" value="27"/>
</bean>

`

Conclusion

• Setting autowire to constructor will inject dependencies using constructor injection.
• Here the bean that has attribute primary set to true will take the preference and will be injected using constructor injection.
• Constructor injection will inject all the values using constructor having four parameters.