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.
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<dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <!-- cglib required for @configuration annotation --> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>3.0</version> </dependency> </dependencies> <properties> <spring.version>4.2.1.RELEASE</spring.version> </properties> |
So your pom.xml will look like:
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<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> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <!-- cglib required for @configuration annotation --> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>3.0</version> </dependency> </dependencies> <properties> <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 .
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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
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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
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<?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
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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.
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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 |
7. Source code
Bingo!! we are done with spring java based configuaration.
Great Example to start