XML방식을 Java Configuration방식으로 변경해보는 실습, Annotation을 활용함

spring/di/ExamAppConfig.java

@@ -0,0 +1,20 @@
+package spring.di;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+import spring.di.entity.Exam;
+import spring.di.entity.NewlecExam;
+
+@ComponentScan( { "spring.di.ui", "spring.di.entity" })
+@Configuration
+public class ExamAppConfig {
+	
+	// 메소드 명이 bean id와같이 식별자 역할을 해준다.
+	@Bean
+	public Exam exam() {
+		return new NewlecExam();
+	}
+
+}

spring/di/Program.java

@@ -1,36 +1,20 @@
 package spring.di;
 
 import org.springframework.context.ApplicationContext;
-import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
-import spring.di.entity.Exam;
-import spring.di.entity.NewlecExam;
 import spring.di.ui.ExamConsole;
 
 public class Program {
 
 	public static void main(String[] args) {
 
-		//ExamConsole console = new InlineExamConsole(exam); // DI
-		//ExamConsole console = new GridExamConsole(exam);
-
-		/*
-			new InlineExamConsole(exam)
-			new FridExamConsole(exam)
-			
-			같은 메서드를 호출하게되는 위 코드의 수정을 대신해줄 수 있도록 하는 기능이 Spring의 DI다.
-
-		 */
-		
-		// 해당 클래스 사용하기위해서
-		// Maven 프로젝트로 바꿔서 빌드툴을 사용하도록 하였고
-		// Maven Repository에가서 Spring context를 dependency해주었음.
 		ApplicationContext context = 
-				new ClassPathXmlApplicationContext("spring/di/setting.xml");
-
+				//new ClassPathXmlApplicationContext("spring/di/setting.xml");
+				new AnnotationConfigApplicationContext(ExamAppConfig.class);
 		
-		//ExamConsole console = (ExamConsole)context.getBean("console");
-		ExamConsole console = context.getBean(ExamConsole.class);
+		//ExamConsole console = (ExamConsole)context.getBean("ExamConsole.class");
+		ExamConsole console = (ExamConsole)context.getBean("console");
 		
 		console.print();
 

spring/di/constSetting.xml

@@ -0,0 +1,47 @@
+<?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:p="http://www.springframework.org/schema/p"
+	xmlns:util="http://www.springframework.org/schema/util"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
+		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd">
+
+	<!-- Exam exam = new NewlecExam(); -->
+	<bean id="exam" class="spring.di.entity.NewlecExam">
+		<constructor-arg type="int" name="kor" value="10" />
+		<constructor-arg type="int" name="eng" value="10" />
+		<constructor-arg type="int" name="math" value="10" />
+		<constructor-arg type="int" name="com" value="10" />
+	</bean>
+	
+	<bean id="exam2" class="spring.di.entity.NewlecExam">
+		<constructor-arg type="int" name="kor" value="20" />
+		<constructor-arg type="int" name="eng" value="20" />
+		<constructor-arg type="int" name="math" value="20" />
+		<constructor-arg type="int" name="com" value="20" />
+	</bean>
+
+	<!-- ExamConsole console = new GridExamConsole(); -->
+	<bean id="console" class="spring.di.ui.InlineExamConsole">
+		<!-- console.setExam(exam); -->
+		<property name="exam" ref="exam" />
+	</bean>
+
+	<!-- 첫번째 방법, constructor-arg태그에 list태그 사용 -->	
+	<bean id="exams" class="java.util.ArrayList">
+		<constructor-arg>
+			<list>
+				<ref bean="exam" />
+				<ref bean="exam2" />
+			</list>
+		</constructor-arg>
+	</bean>
+	
+	<!-- 두번째 방법, util 네임스페이스를 사용해서 표현 -->	
+	<util:list id="exams2" list-class="java.util.ArrayList">
+		<ref bean="exam" />
+		<ref bean="exam2" />
+	</util:list>
+	
+	
+</beans>

spring/di/entity/NewlecExam.java

@@ -7,16 +7,31 @@ public class NewlecExam implements Exam {
 	private int math;
 	private int com;
 	
+	public NewlecExam() {
+		
+	}
+	
+	public NewlecExam(int kor, int eng, int math, int com) {
+		this.kor=kor;
+		this.eng=eng;
+		this.math=math;
+		this.com=com;
+	}
+	
 	@Override
 	public int total() {
-		// TODO Auto-generated method stub
 		return kor+eng+math+com;
 	}
 
 	@Override
 	public float avg() {
-		// TODO Auto-generated method stub
 		return total() / 4.0f;
 	}
 
+	@Override
+	public String toString() {
+		return "NewlecExam [kor=" + kor + ", eng=" + eng + ", math=" + math + ", com=" + com + "]";
+	}
+	
+	
 }

spring/di/entity/TaesanExam.java

@@ -0,0 +1,43 @@
+package spring.di.entity;
+
+import org.springframework.beans.factory.annotation.Value;
+
+public class TaesanExam implements Exam {
+
+	@Value("10")
+	private int kor;
+	@Value("20")
+	private int eng;
+	@Value("30")
+	private int math;
+	@Value("40")
+	private int com;
+	
+	public TaesanExam() {
+		
+	}
+	
+	public TaesanExam(int kor, int eng, int math, int com) {
+		this.kor=kor;
+		this.eng=eng;
+		this.math=math;
+		this.com=com;
+	}
+	
+	@Override
+	public int total() {
+		return kor+eng+math+com;
+	}
+
+	@Override
+	public float avg() {
+		return total() / 4.0f;
+	}
+
+	@Override
+	public String toString() {
+		return "NewlecExam [kor=" + kor + ", eng=" + eng + ", math=" + math + ", com=" + com + "]";
+	}
+	
+	
+}

spring/di/setting.xml

@@ -1,15 +1,10 @@
 <?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.xsd">
+	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-4.3.xsd">
 
-	<!-- Exam exam = new NewlecExam(); -->
-	<bean id="exam" class="spring.di.entity.NewlecExam" />
-
-	<!-- ExamConsole console = new GridExamConsole(); -->
-	<bean id="console" class="spring.di.ui.InlineExamConsole">
-		<!-- console.setExam(exam); -->
-		<property name="exam" ref="exam" />
-	</bean>
+	<context:component-scan base-package="spring.di.ui, spring.di.entity" />
 
 </beans>

spring/di/ui/InlineExamConsole.java

@@ -1,21 +1,34 @@
 package spring.di.ui;
 
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Component;
+
 import spring.di.entity.Exam;
 
+@Component("console")
 public class InlineExamConsole implements ExamConsole {
 
+	//@Qualifier("exam1")
+	@Autowired(required=false)
 	private Exam exam;		
-	
+
 	public InlineExamConsole() {
+		System.out.println("기본생성자");
 	}
-	
+
 	public InlineExamConsole(Exam exam) {		
 		this.exam = exam;
 	}
 
 	@Override
 	public void print() {
-		System.out.printf("total is %d, avg is %f\n", exam.total(), exam.avg());
+		if(exam != null ) {
+			System.out.println(" 현재 생성된 Exam 의 클래스는 ?? " + exam.getClass());
+			System.out.printf("total is %d, avg is %f\n", exam.total(), exam.avg());
+		}
+		else
+			System.out.println(" null 임다 ");
 	}
 
 	@Override