Why am I accessing the class that I shouldn't?

[Nani Ksowy]

HelloSpringApp.java:

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class HelloSpringApp {
    public static void main(String[] args) {

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

        Coach theCoach = context.getBean("myCoach", Coach.class);

        System.out.println(theCoach.getDailyWorkout());
        System.out.println(theCoach.getDailyFortune());

        context.close();
    }
}

GymCoach.java:

public class GymCoach implements Coach {

    private FortuneService fortuneService;

    public GymCoach(FortuneService fortuneService) {
        this.fortuneService = fortuneService;
    }

    @Override
    public String getDailyWorkout() {
        return "Heavy weight bench presses";
    }

    @Override
    public String getDailyFortune() {
        return fortuneService.getFortune();
    }
}

And applicationContext.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.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd">

    <bean id="myFortuneService"
          class="com.xxx.springdemo.SadFortuneService">
    </bean>

    <bean id="myCoach"
          class="com.xxx.springdemo.GymCoach">
          <constructor-arg ref="myFortuneService"/>
    </bean>


    <bean id="myCricketCoach"
          class="com.xxx.springdemo.CricketCoach">
          <property name="fortuneService" ref="myFortuneService"/>
    </bean>

</beans>

When executing above code (plus some basic interfaces and FortuneServices, probably doesn't matter), I get the following output:

Inside CRICKET-COACH no-arg constructor
Inside CRICKET-COACH setter method
Heavy weight bench presses
Not the best day it might be!

And here's the CricketCoach class:

public class CricketCoach implements Coach {

    private FortuneService fortuneService;

    public CricketCoach() {
        System.out.println("Inside CRICKET-COACH no-arg constructor");
    }

    public void setFortuneService(FortuneService fortuneService) {
        System.out.println("Inside CRICKET-COACH setter method");
        this.fortuneService = fortuneService;
    }

    @Override
    public String getDailyWorkout() {
        return "Crickettors don't work out";
    }

    @Override
    public String getDailyFortune() {
        return fortuneService.getFortune();
    }
}

So basically:
Inside HelloSpringApp I am creating theCoach object from a "myCoach" bean that's configured inside .xml.
myCoach bean is tied to GymCoach.

Yet for some reason, those "debugging sysouts" are printed as well. From CricketCoach. Why would my program access CricketCoach class? Once again, inside .xml myCoach is tied to GymCoach; not to CricketCoach.

[Junilu Lacar]

It has nothing to do with your myCoach bean. When Spring initialized, it creates all the beans you declared in your application context, so when lines 20-23 of your .xml file are processed, the CricketCoach constructor is invoked and the setFortuneService method is called to inject the service bean.

[Nani Ksowy]

Alright, thanks.