• Java
    • JAXB Tutorial
      • What is JAXB
      • JAXB Marshalling Example
      • JAXB UnMarshalling Example
  • Spring Tutorial
    • Spring Core Tutorial
    • Spring MVC Tutorial
      • Quick Start
        • Flow Diagram
        • Hello World Example
        • Form Handling Example
      • Handler Mapping
        • BeanNameUrlHandlerMapping
        • ControllerClassNameHandlerMapping
        • SimpleUrlHandlerMapping
      • Validation & Exception Handling
        • Validation+Annotations
        • Validation+ResourceBundle
        • @ExceptionHandler
        • @ControllerAdvice
        • Custom Exception Handling
      • Form Tag Library
        • Textbox Example
        • TextArea Example
        • Password Example
        • Dropdown Box Example
        • Checkboxes Example
        • Radiobuttons Example
        • HiddenValue Example
      • Misc
        • Change Config file name
    • Spring Boot Tutorial
  • Hibernate Tutorial
  • REST Tutorial
    • JAX-RS REST @PathParam Example
    • JAX-RS REST @QueryParam Example
    • JAX-RS REST @DefaultValue Example
    • JAX-RS REST @Context Example
    • JAX-RS REST @MatrixParam Example
    • JAX-RS REST @FormParam Example
    • JAX-RS REST @Produces Example
    • JAX-RS REST @Consumes Example
    • JAX-RS REST @Produces both XML and JSON Example
    • JAX-RS REST @Consumes both XML and JSON Example
  • Miscellaneous
    • JSON Parser
      • Read a JSON file
      • Write JSON object to File
      • Read / Write JSON using GSON
      • Java Object to JSON using JAXB
    • CSV Parser
      • Read / Write CSV file
      • Read/Parse/Write CSV File – OpenCSV
      • Export data into a CSV File
      • CsvToBean and BeanToCsv – OpenCSV

JavaInterviewPoint

Java Development Tutorials

Spring 3 JavaConfig Example

March 31, 2015 by javainterviewpoint Leave a Comment

In our previous article Spring hello world example we have used the classic XML to define our configurations. JavaConfig has been added since Spring 3.o, which lets the developer to add all the configuration into Java class rather than into XML file. Still, you have the option to add configuration in the XML format but JavaConfig is just an alternate way of adding bean definition.

Now let’s see the difference between defining bean in classic XML format and using JavaConfig.
JavaConfig way

@Configuration
public class HelloWorldConfig 
{
    @Bean(name="helloWorld")
    public HelloWorld getHelloWorld()
    {
        return new HelloWorld();
    }
}

Above JavaConfig is equivalent to the below XML Configuration

Classic XML

<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="com.javainterviewpoint.HelloWorld"></bean>
</beans>

Lets Now see the full JavaConfig example

Folder Structure:

  1. Create a new Java Project  “SpringCoreTutorial” and create a package for our src files “com.javainterviewpoint“
  2. 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
    spring-context-3.2.9.RELEASE.jar
    spring-expression-3.2.9.RELEASE.jar

  3. Create the Java classes HelloWorld.java, HelloWorldConfig.java and Logic.java under  com.javainterviewpoint folder.

HelloWorldConfig.java

  • The @Configuration annotation indicates that this class defines one or more @Bean method which will be processed by the Spring Container to generate the Bean definitions and service at runtime.
  •  The @Bean annotation indicates a particular beans definition which will be processed at runtime.
package com.javainterviewpoint;

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

@Configuration
public class HelloWorldConfig 
{
    @Bean(name="helloWorld")
    public HelloWorld getHelloWorld()
    {
        return new HelloWorld();
    }
}

HelloWorld.java

Our HelloWorld class simply has a method display() which will be called from our Logic class

package com.javainterviewpoint;

public class HelloWorld
{
    public void display(String message)
    {
        System.out.println(message);
    }
}

Logic.java

  • Through AnnotationConfigApplicationContext we will get the context by reading our HelloWorldConfig class
  • HelloWorld instance is obtained by calling the getBean() method over the applicationContext.
  • The parameter passed to the getBean(“helloWorld”) should be the name defined in @Bean annotation @Bean(name=”helloWorld”)
package com.javainterviewpoint;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Logic 
{
    public static void main(String args[])
    {
        //Reading the HelloWorldConfig through ApplicationContext
        ApplicationContext applicationContext =new AnnotationConfigApplicationContext(HelloWorldConfig.class);
        //Get the HelloWorld instance
        HelloWorld helloWorld = (HelloWorld)applicationContext.getBean("helloWorld");
        //Call the display() method of helloWorld class
        helloWorld.display("Hello World via JavaConfig");
        
    }
}

Output

Upon running our Logic class we will get the below output

Hello World via JavaConfig

Other interesting articles which you may like …

  • Spring Bean Scopes Example
  • Autowiring in Spring
  • Spring Autowiring byName Example
  • Spring Autowiring byType Example
  • Spring Autowiring constructor Example
  • How to Instantiate Spring IoC Container
  • How to Create and Configure Beans in the Spring IoC Container
  • Spring Constructor Injection – Resolving Ambiguity
  • How to create Spring Beans Using Spring FactoryBean
  • How to specify Spring Bean Reference and Spring Inner Bean
  • Spring Dependency Checking and Spring @Required Annotation
  • @Autowired, @Resource, @Qualifier, @Inject Annotation
  • Spring Bean Life Cycle – Bean Initialization and Destruction
  • Static Factory Method & Instance Factory Method

Filed Under: J2EE, Java, Spring, Spring Core, Spring Tutorial Tagged With: JavaConfig, Spring 3

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Java Basics

  • JVM Architecture
  • Object in Java
  • Class in Java
  • How to Set Classpath for Java in Windows
  • Components of JDK
  • Decompiling a class file
  • Use of Class.forName in java
  • Use Class.forName in SQL JDBC

Oops Concepts

  • Inheritance in Java
  • Types of Inheritance in Java
  • Single Inheritance in Java
  • Multiple Inheritance in Java
  • Multilevel Inheritance in Java
  • Hierarchical Inheritance in Java
  • Hybrid Inheritance in Java
  • Polymorphism in Java – Method Overloading and Overriding
  • Types of Polymorphism in java
  • Method Overriding in Java
  • Can we Overload static methods in Java
  • Can we Override static methods in Java
  • Java Constructor Overloading
  • Java Method Overloading Example
  • Encapsulation in Java with Example
  • Constructor in Java
  • Constructor in an Interface?
  • Parameterized Constructor in Java
  • Constructor Chaining with example
  • What is the use of a Private Constructors in Java
  • Interface in Java
  • What is Marker Interface
  • Abstract Class in Java

Java Keywords

  • Java this keyword
  • Java super keyword
  • Final Keyword in Java
  • static Keyword in Java
  • Static Import
  • Transient Keyword

Miscellaneous

  • newInstance() method
  • How does Hashmap works internally in Java
  • Java Ternary operator
  • How System.out.println() really work?
  • Autoboxing and Unboxing Examples
  • Serialization and Deserialization in Java with Example
  • Generate SerialVersionUID in Java
  • How to make a class Immutable in Java
  • Differences betwen HashMap and Hashtable
  • Difference between Enumeration and Iterator ?
  • Difference between fail-fast and fail-safe Iterator
  • Difference Between Interface and Abstract Class in Java
  • Difference between equals() and ==
  • Sort Objects in a ArrayList using Java Comparable Interface
  • Sort Objects in a ArrayList using Java Comparator

Follow

  • Coding Utils

Useful Links

  • Spring 4.1.x Documentation
  • Spring 3.2.x Documentation
  • Spring 2.5.x Documentation
  • Java 6 API
  • Java 7 API
  • Java 8 API
  • Java EE 5 Tutorial
  • Java EE 6 Tutorial
  • Java EE 7 Tutorial
  • Maven Repository
  • Hibernate ORM

About JavaInterviewPoint

javainterviewpoint.com is a tech blog dedicated to all Java/J2EE developers and Web Developers. We publish useful tutorials on Java, J2EE and all latest frameworks.

All examples and tutorials posted here are very well tested in our development environment.

Connect with us on Facebook | Privacy Policy | Sitemap

Copyright ©2023 · Java Interview Point - All Rights Are Reserved ·