Starting with Spring Framework (Hello World Example)

This article will talk about the rudimentary steps required to set up a simple Hello World application in Java using Spring Framework.

Download Links

• Eclipse
• Spring Framework
• Commons Logging
• ANTLR

Steps

1. Create a new Java Project in Eclipse

2. In Project Explorer,
right click on project name,
Build Path,
Configure,
Libraries Tab,
Add External Jars
Browse & add
All the executable Jar files from spring-framework-3.1.0.M2/dist directory.
antlr-runtime-4.2.1
commons-logging-1.1.3

3. In the src folder create package org.techmight

4. Add the following two classes in org.techmight package.

HelloWorld.java

package org.techmight;

/**
 * @author TechMight Solutions
 */

public class HelloWorld {

 private String message;

 public String getMessage() {
  return ("Your Message : " + message);
 }

 public void setMessage(String message) {
  this.message = message;
 }
}

MainApp.java (this class will have main method)

package org.techmight;

/**
 * @author TechMight Solutions
 */

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {

 public static void main(String[] args) {
  ApplicationContext context = new ClassPathXmlApplicationContext(
    "spring-config.xml");
  HelloWorld obj = (HelloWorld) context.getBean("helloWorld");

  String response = obj.getMessage();
  System.out.println(response);
 }
}

5. Create spring-config.xml in src folder with the following bean configuration.

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

<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="helloWorld" class="org.techmight.HelloWorld"> 
  <property name="message" value="Hello World from TechMight Solutions!"/>
 </bean>
 
</beans>

6. Finally right click on MainApp.java,
Run as
Java application

Output

Your Message : Hello World from TechMight Solutions!

Advantage

The default values of the member variables can be changed by making the changes in spring-config.xml file without changing any Java code.

Implementation

E.g. Consider a class which uses some configuration variables for database communication. If there is any change in any of these configurations, there is no need to make modifications in java code and then recompile it. Only setting the proper configuration in spring-config.xml file will do the work.