ApplicationContext component scan : ApplicationContext « Spring « Java Tutorial

1. Java Tutorial
2. Spring
3. ApplicationContext

File: context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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.xsd
                http://www.springframework.org/schema/context
                http://www.springframework.org/schema/context/spring-context.xsd
                http://www.springframework.org/schema/aop
                http://www.springframework.org/schema/aop/spring-aop.xsd">

    <aop:aspectj-autoproxy />

    <context:component-scan base-package="bean">
        <context:include-filter type="annotation" expression="org.aspectj.lang.annotation.Aspect"/>
    </context:component-scan>


</beans>

File: Main.java

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import bean.Helper;
import bean.HelperDemo;

public class Main {
  public static void main(String[] args) throws Exception {
    ApplicationContext ac = new ClassPathXmlApplicationContext(
        "context.xml");
    HelperDemo hd1 = (HelperDemo) ac.getBean("helperDemo");
    hd1.someOperation();
    System.out.println(hd1);
    HelperDemo hd2 = (HelperDemo) ac.getBean("helperDemo");
    hd2.someOperation();
    System.out.println(hd2);
    Helper helper = (Helper) ac.getBean("helper");
    System.out.println(helper);
  }
}

File: Helper.java

package bean;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component("helper")
@Scope(BeanDefinition.SCOPE_PROTOTYPE)
public class Helper {
    private int count;

    public void work() {
        this.count++;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append("Helper");
        sb.append("{count=").append(count);
        sb.append('}');
        return sb.toString();
    }
}

File: HelperDemo.java

package bean;



import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component
@Scope(BeanDefinition.SCOPE_PROTOTYPE)
public class HelperDemo {
    @Autowired
    private Helper helper;

    public void setHelper(Helper helper) {
        this.helper = helper;
    }

    public void someOperation() {
        this.helper.work();
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append("HelperDemo");
        sb.append("{helper=").append(helper);
        sb.append('}');
        return sb.toString();
    }
}

28.2.ApplicationContext
	28.2.1.	ApplicationContext component scan
	28.2.2.	Component Filter Assignable
	28.2.3.	Search By Base Package
	28.2.4.	Implements ApplicationListener
	28.2.5.	Implements ApplicationEvent Publisher Aware
	28.2.6.	Filter By Annotation
	28.2.7.	ApplicationContext Aware
	28.2.8.	ApplicationContext And BeanFactory PostProcessor