Dependency Injection via Constructor in spring


This is 7 of 16 parts of tutorial series

Tutorial Content: Spring tutorial for beginners

As the name implies, using constructor spring container will inject the dependencies.
For configuring spring in your eclipse ide please refer  hello world example

Dependency Injection via Constructor

We will create a simple class which has countryName and capital as attributes.
Create under package org.arpit.java2blog.Copy following content into

Create under package org.arpit.java2blog.Above Country class contains object of this class.Copy following content into


Here We have declared two beans with corresponding ids.
1.Class Country with id as “CountryBean”
2.Class Capital with id as “CapitalBean”
constructor-arg tag is used for providing argument to bean’ s constructor.type is for declaring data types and index defines position in constructor’s argument.
In above xml,Two arguments are passed.
1. India as string
2.CapitalBean ‘s reference
Property’s value tag is for assigning value to corresponding attribute. so In above xml file,we have assigned capitalName attribute of Capital class with value as Delhi

Property’s ref tag is used for assigning reference to the corresponding attribute. so In above xml file, we have assigned reference of Capital class to capital attribute of Country class.

This class contains main function.Create under package org.arpit.java2blog.
You can note here that we have used ClassPathXmlApplicationContext for getting bean here.There are various ways for getting beans.In hello world example we have used XmlBeanFactory for getting beans.

5.Run it

When you will run above application, you will get following as output.

That’s all about Spring Dependency Injection via Constructor.
In next post,we will see spring bean scopes


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