Java/Spring/IoC Construct

Constructor Confusion

/*
Pro Spring
By Rob Harrop
Jan Machacek
ISBN: 1-59059-461-4
Publisher: Apress
*/
///////////////////////////////////////////////////////////////////////
//File: beans.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <!-- ctor confusion -->
    <bean id="constructorConfusion" class="ConstructorConfusion">
        <constructor-arg type="int">
            <value>90</value>
        </constructor-arg>
    </bean>
</beans>

///////////////////////////////////////////////////////////////////////

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;
public class ConstructorConfusion {
    private String someValue;
    public ConstructorConfusion(String someValue) {
        System.out.println("ConstructorConfusion(String) called");
        this.someValue = someValue;
    }
    public ConstructorConfusion(int someValue) {
        System.out.println("ConstructorConfusion(int) called");
        this.someValue = "Number: " + Integer.toString(someValue);
    }
    public static void main(String[] args) {
        BeanFactory factory = new XmlBeanFactory(new FileSystemResource(
                "build/beans.xml"));
        ConstructorConfusion cc = (ConstructorConfusion) factory.getBean("constructorConfusion");
        System.out.println(cc);
    }
    public String toString() {
        return someValue;
    }
}

Default Creator Example

/*
Pro Spring
By Rob Harrop
Jan Machacek
ISBN: 1-59059-461-4
Publisher: Apress
*/

///////////////////////////////////////////////////////////////////////////////////////
//File: dpac.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="autoBean" class="AutoBean"/>
    <bean id="otherBean" class="OtherBean"/>
</beans>

///////////////////////////////////////////////////////////////////////////////////////
public class AutoBean {
    public void foo() {
        System.out.println("foo()");
    }
}
///////////////////////////////////////////////////////////////////////////////////////
public class OtherBean {
    public void foo() {
        System.out.println("foo()");
    }
}
///////////////////////////////////////////////////////////////////////////////////////
import org.springframework.aop.support.AopUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class DefaultCreatorExample {
    public static void main(String[] args) {
        ApplicationContext ctx = new FileSystemXmlApplicationContext(
        "build/dpac.xml");
        
        AutoBean autoBean = (AutoBean)ctx.getBean("autoBean");
        OtherBean otherBean = (OtherBean)ctx.getBean("otherBean");
        
        autoBean.foo();
        System.out.println(AopUtils.isAopProxy(autoBean));
        
        otherBean.foo();
        System.out.println(AopUtils.isAopProxy(otherBean));
    }
}