Spring: UnsatisfiedDependencyException even though qualifier property matches - spring

Question

Summary: I am working with some sample Spring code (from javabrains.io). Basically this code illustrates the use of the #Qualifier annotation in the Java file. One of the bean elements (in spring.xml) has a qualifier that matches the value of the #Qualifier annotation but even then UnsatisfiedDependencyException is thrown.
Details: The Circle class has a method which accepts a Point object and which has the following annotations:
#Autowired
#Qualifier("circleRelated")
In spring.xml we have three Point beans: pointA, pointB and pointC. pointA has the property attribute set to circleRelated. One would expect that since this bean meets the qualifier criterion (i.e. value = "circleRelated"), at initialization time autowiring should complete without any hitch. However, UnsatisfiedDependencyException is thrown. The source code follows:
Point.java
package org.koushik.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;
}
}
Circle.java
package org.koushik.javabrains;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
public class Circle {
private Point center;
public Point getCenter() {
return center;
}
#Autowired
#Qualifier("circleRelated")
public void setCenter(Point center) {
this.center = center;
}
public void draw() {
System.out.println("Drawing Circle");
System.out.println("Circle: Center point is: " + center.getX() + ", " + center.getY());
}
}
DrawingApp.java
package org.koushik.javabrains;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DrawingApp {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
Circle circle = (Circle) context.getBean("circle");
circle.draw();
}
}
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"
xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"
xmlns:context="http://www.springframework.org/schema/context">
<bean id="pointA" class="org.koushik.javabrains.Point">
<qualifier value="circleRelated"/>
<property name="x" value ="0"/>
<property name="y" value ="0"/>
</bean>
<bean id="pointB" class="org.koushik.javabrains.Point">
<property name="x" value ="-20"/>
<property name="y" value ="0"/>
</bean>
<bean id="pointC" class="org.koushik.javabrains.Point">
<property name="x" value ="20"/>
<property name="y" value ="0"/>
</bean>
<bean id="circle" class="org.koushik.javabrains.Circle">
</bean>
<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
</beans>

Answer 1

You are missing
<context:annotation-config/>
tag in your spring.xml
Source
Use of these annotations also requires that certain BeanPostProcessors
be registered within the Spring container. As always, these can be
registered as individual bean definitions, but they can also be
implicitly registered by including the following tag in an XML-based
Spring configuration (notice the inclusion of the 'context'
namespace):
On a side note , any specific reason you are using xml based configuration ? Though spring supports xml configurations , it is long since people have moved to Annotations based configuration.I recommend that it is worth exploring annotations based route.