In this example, we will learn how to create a simple hello world example in Spring 3.0.
Folder Structure:
- Create a new Java Project “SpringCoreTutorial” and create a package for our src files “com.javainterviewpoint“
- Add the required libraries to the build path. Java Build Path ->Libraries ->Add External JARs and add the below jars.
commons-logging-1.1.1.jar
spring-beans-3.2.9.RELEASE.jar
spring-core-3.2.9.RELEASE.jar - Create the Java classes HelloWorldBean.java and Logic.java under com.javainterviewpoint folder.
- Place the SpringConfig.xml under the src directory
HelloWorldBean.java
- Our HelloWorldBean class contains property message, for which we will set the value through our Logic class.
- The show() method prints the value which has been set by the Logic class
package com.javainterviewpoint; public class HelloWorldBean { private String message; public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } public void show() { System.out.println("Welcome to "+message+" - JavaInterviewPoint"); } }
Logic.java
- In our Logic class, We use Resource to read the configurationfile(SpringConfig.xml).
- We will get our “HelloWorldBean” instance through the BeanFactory which reads up all the bean available in the Configuration File.
- We set the value to message property of the HelloWorldBean and we will call our show() method.
package com.javainterviewpoint; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.xml.XmlBeanFactory; import org.springframework.core.io.ClassPathResource; import org.springframework.core.io.Resource; public class Logic { public static void main(String args[]) { //Create a Resource to read the configuration file Resource resource = new ClassPathResource("SpringConfig.xml"); //Read the beanfactory of the configuration file BeanFactory bf = new XmlBeanFactory(resource); //Get the HelloWorldBean object HelloWorldBean helloWorldBean = (HelloWorldBean)bf.getBean("helloWorldBean"); //Set value to the message property in the helloWorldBean class helloWorldBean.setMessage("Hello World"); //Lets now call the show() method helloWorldBean.show(); } }
SpringConfig.xml
All the beans which is available will be declared in the SpringConfig file
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd"> <beans> <bean id="helloWorldBean" class="com.javainterviewpoint.HelloWorldBean"></bean> </beans>
Output
Once we run our Logic cass we will get the below output
Welcome to Hello World - JavaInterviewPoint
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