Using #Component for bean throws error. NoSuchBeanDefinitionException - spring

Question

I'm trying to create a simple spring app, but when i use #Component annotation for a bean instead of defining it in spring.xml file, I'm getting this error.
Aug 09, 2017 11:06:03 AM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext#7e32c033: startup date [Wed Aug 09 11:06:03 IST 2017]; root of context hierarchy
Aug 09, 2017 11:06:03 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring.xml]
Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'oval' available
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:687)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1207)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078)
at org.sumit.javabrains.DrawingApp.main(DrawingApp.java:24)
My Classes are al follows:
1. DrawingApp.java (main class)
public package org.sumit.javabrains;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DrawingApp {
public static void main(String[] args) throws InterruptedException {
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
Oval oval = (Oval) context.getBean("oval");
oval.draw();
}
}
2. Spring.xml
<?xml version = "1.0" encoding = "UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<context:component-scan base-package="com.sumit.javabrains" />
<context:annotation-config />
<bean id="focus" class="org.sumit.javabrains.Point" scope="singleton">
<property name="x" value="-7" />
<property name="y" value="8" />
</bean>
</beans>
3 Point.java
package org.sumit.javabrains;
public class Point {
private int x;
private int y;
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
}
4 Oval.java
package org.sumit.javabrains;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
#Component
public class Oval {
private Point focus;
public Point getFocus() {
return focus;
}
#Resource
public void setFocus(Point focus) {
this.focus = focus;
}
public void draw() {
System.out.println("Point focus is: ("+focus.getX()+", "+focus.getY()+")");
}
}
could someone be able to help what caused this issue. I'm using spring 4.3.10 RELEASE

Answer 1

That's because your component scan is scanning the wrong packages
<context:component-scan base-package="com.sumit.javabrains" /> - Wrong
It should be scanning as follows:
<context:component-scan base-package="org.sumit.javabrains" /> - Correct

Answer 2

you must define all your bean in spring.xml. in this scenario you missed the Oval class in you spring configuration files. define the Oval class as a bean in your spring.xml file.
or
edit your component-scan tag and put the correct package.

Answer 3

Two thing went wrong here.
1. You've mentioned wrong base package in your xml file
com.sumit.javabrains must be replaced with org.sumit.javabrains
Replace #Resource with #Resource #Qualifier("focus").By default beans marked with ‘#Component’ will have the same name as the class

Answer 4

Try using #ComponentScan instead of #Component on top of the Oval class.

Answer 5

I wasn't using a spring.xml file (just the default spring boot configuration instead), my #SpringBootApplication annotated class was one package level deeper than my #Component class, which made that the #Component class wasn't picked up.
E.g.:
com.company.base/ComponentAnnotatedClass.java
com.company.base.application/MySpringBootApplication.java