Spring 3 hello world example

This tutorial shows you how to create a simple hello world example in Spring 3.0.
Technologies used in this article :

• Spring 3.0.5.RELEASE
• Maven 3.0.3
• Eclipse 3.6
• JDK 1.6.0.13

P.S
Spring 3.0, at least JDK 1.5 is required to work.

Spring 3.0 dependencies
In Spring 2.5.x, almost the entire Spring modules are grouped into a single spring.jar file. Since Spring 3.0, every modules are split into an individual jar file, for example, spring-core, spring-expression, spring-context, spring-aop and etc.

1. Generate project structure with Maven

Issue below Maven command to create a standard Java project structure.

mvn archetype:generate -DgroupId=com.mkyong.core -DartifactId=Spring3Example -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

2. Convert to Eclipse project

Convert Maven style project to Eclipse’s style project, and import into Eclipse IDE.`

mvn eclipse:eclipse

2. Add Spring 3.0 dependency

Add the Spring 3.0 dependencies listed below in Maven’s pom.xml file. The Spring dependencies are available for download via Maven central repository.

File : pom.xml

<?xml version="1.0"?>
<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mkyong.core</groupId>
    <artifactId>Spring3Example</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Spring3Example</name>
    <url>http://maven.apache.org</url>
    <properties>
        <spring.version>3.0.5.RELEASE</spring.version>
    </properties>
    <dependencies>
        <!-- Spring 3 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
    </dependencies>
</project>

3. Spring bean

A simple Spring bean.

package com.mkyong.core;

/** * Spring bean * */
public class HelloWorld { 
    private String name; 
    public void setName(String name) { 
        this.name = name; 
    } 
    public void printHello() { 
        System.out.println("Spring 3 : Hello ! " + name); 
    }
}

4. Spring bean configuration file

Create a Spring configuration file, and declare all the available Spring beans.

File : SpringBeans.xml

<?xml version="1.0"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
    <bean id="helloBean" class="com.mkyong.core.HelloWorld">
        <property name="name" value="Mkyong" />
    </bean>
</beans>

5. Review project structure

Review directory structure as follows

Spring3-hello-world-example.png

6. Run It

Run it.

package com.mkyong.core;
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");  
        HelloWorld obj = (HelloWorld) context.getBean("helloBean");  
        obj.printHello(); 
    }
}

7. Output

Spring 3 : Hello ! Mkyong