In Spring 3 we can also create a bean using java file instead of XML.It is alternate way to create the bean, you can also use xml based configuration.

HelloWorld.java

package com.babita;

public class  HelloWorld {


    public void printMessage(String message)
    {
        System.out.println("Hello World From "+message);
    }

}

JavaConfig.java

package com.babita;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class JavaConfig {

    @Bean(name="helloBean")
    public HelloWorld helloWorld() {
        return new HelloWorld();
    }

}

Now define the below class to run the code:

MainApp.java

package com.babita;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {

public static void main(String[] args) 
{
ApplicationContext context = new                                                 AnnotationConfigApplicationContext(JavaConfig.class);

         HelloWorld obj = (HelloWorld) context.getBean("helloBean");
         obj.printMessage("Spring 3.0");

    }
}

In above Example we can see that the JavaConfig.java file can put @Configuration annotation to indicate that is core spring configuration file and @Bean annotation defines the name of bean and finally we can load the JavaConfig.java class via AnnotationConfigApplicationContext to instantiate the bean.

Hope this will help you :)