[자바강의,스프링강의(SpringFramework/Boot),IT실무교육추천]#21.컬렉션을이용한빈주입(XML,어노테이션방식)

#21.컬렉션을이용한빈주입(XML,어노테이션방식)

컬렉션 주입(Collection Injection), XML 방식

n  빈에서 개별 빈 이나 값이 아닌 객체의 컬렉션에  접근해야 되는 경우가 있는데 <list>, <map>, <set>, <prop>를 사용한다. 자바에서 Properties 클래스는 property 값으로 String을 지원하므로 String만 넘길 수 있다.

[app-context5.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 http://www.springframework.org/schema/beans/spring-beans-4.2.xsd">

<bean id="onj" name="onjName" class="onj.injection.collection.Onj"/>

<bean id="sample" class="onj.injection.collection.CollectionExam">

<property name="map">

           <map>

                     <entry key="someValue">

                                <value>hello map...</value>

                     </entry>

                     <entry key="someBean">

                                <ref bean="onj"/>

                     </entry>

           </map>

</property>

<property name="set">

           <set>

                     <value>hello list...</value>

                     <ref bean="onj"/>

           </set>

</property>

<property name="props">

           <props>

                     <prop key="firstName">Jong Cheol</prop>

                     <prop key="lastName">Lee</prop>

           </props>

</property>

</bean>

</beans>

[CollectionExam.java]

public void display() {

           for(Map.Entry<String, Object> entry:map.entrySet()) {

             System.out.println("Key: " + entry.getKey() + "-" + entry.getValue());

           }

           for(Map.Entry<Object, Object> entry : props.entrySet()) {

             System.out.println("key : " + entry.getKey() + "-" + entry.getValue() );

           }

           for(Object obj : set) {

              System.out.println("value : " + obj);

           }

}

public static void main(String[] args) {

           GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();

           ctx.load("classpath:app-context5.xml");

           ctx.refresh();

           CollectionExam col =  (CollectionExam)ctx.getBean("sample“)

           col.display();

}

컬렉션 주입(Collection Injection), 어노테이션 방식

[app-context6.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"

        xmlns:util="http://www.springframework.org/schema/util"

        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd

               http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd

               http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd">

<context:annotation-config/>

<context:component-scan base-package="onj.collection.annotation" />

<bean id="onj" name="onjName" class="onj.collection.annotation.Onj"/>

<util:map id="map" map-class="java.util.HashMap">

<entry key="someValue">

<value>hello... map</value>

</entry>

<entry key="someBean">

<ref ben="onj"/>

</entry>

</util:map>

<util:properties id="props">

<prop key="firstName">Jong Cheol</prop>

<prop key="lastName">Lee</prop>

</util:properties>

<util:set id="set">

<value>hello.... set</value>

<ref bean="onj"/>

</util:set>

</beans>

[Onj.java]

package onj.collection.annotation;

import org.springframework.stereotype.Service;

@Service("onj")

public class Onj {

           public String toString() {

                     return "my name is OnJ";

           }

}

[CollectionAnnotationExam.java]

…

…

@Service("sample")

public class CollectionAnnotationExam {

@Resource(name="map")

private Map<String, Object> map ;

@Resource(name="props")

private Properties props;

@Resource(name="set")

private Set<Object> set;

…

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