Spring java based configuration example

In this post , we will see how to configure spring with java based configuration. In previous post, we have already seen how to configure spring using xml configuration. Spring provides @configuaration and @Bean annotation for java based configuration.

Steps for spring java based configuration:

Project structure for below project:

1. Create a simple java maven project.

2. Maven dependency

put spring and cglib maven dependency in pom.xml.

<groupId>org.springframework</groupId>

<artifactId>spring-core</artifactId>

<version>${spring.version}</version>

</dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-webmvc</artifactId>

<version>${spring.version}</version>

</dependency>

<groupId>cglib</groupId>

<artifactId>cglib</artifactId>

</dependency>

</dependencies>

<spring.version>4.2.1.RELEASE</spring.version>

</properties>

So your pom.xml will look like:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"<

<modelVersion<4.0.0</modelVersion>

<groupId>org.arpit.java2blog</groupId>

<artifactId>SpringHelloWorldJavaBasedConfiguration</artifactId>

<version>0.0.1-SNAPSHOT</version>

<name>SpringHelloWorldJavaBasedConfiguration</name>

<description>It provides hello world program for java based config

</description>

<groupId>org.springframework</groupId>

<artifactId>spring-core</artifactId>

<version>${spring.version}</version>

</dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-webmvc</artifactId>

<version>${spring.version}</version>

</dependency>

<groupId>cglib</groupId>

<artifactId>cglib</artifactId>

</dependency>

</dependencies>

<spring.version>4.2.1.RELEASE</spring.version>

</properties>

</project>

3. Create Bean class

Create a bean class called country.java in package org.arpit.java2blog.model .

package org.arpit.java2blog.model;

public class Country {

String countryName;

public Country(String countryName) {

this.countryName=countryName;

}

public String getCountryName() {

return countryName;

}

public void setCountryName(String countryName) {

this.countryName = countryName;

}

4. Create application configuration class

This class will have @Configuaration and @Bean annotation .

Create class called ApplicationConfiguration.java in package org.arpit.java2blog.config

package org.arpit.java2blog.config;

import org.arpit.java2blog.model.Country;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

@Configuration

public class ApplicationConfiguration {

@Bean(name="countryObj")

public Country getCountry()

{

return new Country("India");

}

Above file is equivalent to below spring configuration xml

<?xml version="1.0" encoding="UTF-8"?<

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-3.0.xsd"<

<context:annotation-config/<

<bean id="countryObj" class="org.arpit.java2blog.Country" <

<property name="countryName" value="India"/<

</bean<

</beans<

5. Create main class to run the program

Create class called SpringJavaConfigMain.java

package org.arpit.java2blog.main;

import org.springframework.context.ApplicationContext;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import org.arpit.java2blog.config.ApplicationConfiguration;

import org.arpit.java2blog.model.Country;;

public class SpringJavaConfigMain {

public static void main(String[] args) {

@SuppressWarnings("resource")

ApplicationContext appContext = new AnnotationConfigApplicationContext(ApplicationConfiguration.class);

Country countryObj = (Country) appContext.getBean("countryObj");

String countryName=countryObj.getCountryName();

System.out.println("Country name: "+ countryName);

}

6. Run above program

When you run above program, you will get below output.

Feb 19, 2016 4:09:08 PM org.springframework.context.annotation.AnnotationConfigApplicationContext prepareRefresh

INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@2096ed8b: startup date [Fri Feb 19 16:09:08 IST 2016]; root of context hierarchy

Country name: India