DI 설정 방법 - xml

#DI 설정 방법

오늘은 IOC컨테이너 안에 의존하는 객체인 DI를 설정하는 방법을 알아보자 !

총 3가지의 방법이 있다.

1. DI in xml
2. DI in java
3. java 와 xml 같이 사용

 

 

###1. XML파일을 이용한 DI 설정 방법(DI in XML)

 

 

 

​x
// 일단 Student.java 파일 부터 보자
​
package com.javalec.ex;
​
import java.util.ArrayList;
​
public class Student {
​
    private String name;
    private int age;
    private ArrayList<String> hobbys;
    private double height;
    private double weight;
    
    public Student(String name, int age, ArrayList<String> hobbys) {
        this.name = name;
        this.age = age;
        this.hobbys = hobbys;
    }
​
    public void setName(String name) {
        this.name = name;
    }
​
    public void setAge(int age) {
        this.age = age;
    }
​
    public void setHobbys(ArrayList<String> hobbys) {
        this.hobbys = hobbys;
    }
​
    public void setHeight(double height) {
        this.height = height;
    }
​
    public void setWeight(double weight) {
        this.weight = weight;
    }   
}
​
===========================================================================================
​
// 다음으로 Family.java
package com.javalec.ex;
​
public class Family {
    
    private String papaName;
    private String mamiName;
    private String sisterName;
    private String brotherName;
    
    public Family(String papaName,String mamiName) {
        this.papaName = papaName;
        this.mamiName = mamiName;
    }
​
    public String getPapaName() {
        return papaName;
    }
​
    public void setPapaName(String papaName) {
        this.papaName = papaName;
    }
​
    public String getMamiName() {
        return mamiName;
    }
​
    public void setMamiName(String mamiName) {
        this.mamiName = mamiName;
    }
​
    public String getSisterName() {
        return sisterName;
    }
​
    public void setSisterName(String sisterName) {
        this.sisterName = sisterName;
    }
​
    public String getBrotherName() {
        return brotherName;
    }
​
    public void setBrotherName(String brotherName) {
        this.brotherName = brotherName;
    }
}
​
===========================================================================================
​
// 이렇게 두 .java 파일이 있을 때 DI설정 방법
// 첫번째 !
​
<?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">
​
    <bean id="student1" class="com.javalec.ex.Student">
        <constructor-arg value ="홍길동"/>
        <constructor-arg value ="27"/>
        <constructor-arg>
            <list>
                <value>게임</value>
                <value>산책</value>
                <value>운동</value>
            </list>
        </constructor-arg>
        
        <property name="height" value="172"/>
        <property name="weight" value="72"/>
    </bean>
    
    <bean id="studentInfo" class="com.javalec.ex.StudentInfo">
    <property name="student"> 
        <ref bean="student1"/>
    </property>
    </bean>
</beans>
​
// constructor-age 는 생성자 에서 값을 넣을 때
// property 는 setter를 이용해서 값을 넣을 때
​
===========================================================================================
​
// 두번쨰
​
<?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:c="http://www.springframework.org/schema/c"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
​
    <bean id="student3" class="com.javalec.ex.Student">
        <constructor-arg value ="홍홍홍"/>
        <constructor-arg value ="18"/>
        <constructor-arg>
            <list>
                <value>게임</value>
                <value>산책</value>
                <value>운동</value>
            </list>
        </constructor-arg>
        
        <property name="height" value="162"/>
        <property name="weight" value="50"/>
    </bean>
​
    <bean id ="family" class="com.javalec.ex.Family" c:papaName="홍아빠" c:mamiName="홍엄마" p:sisterName="홍스터">
    <property name="brotherName" value="홍브라"></property>
    </bean> 
</beans>
​
​
// 여기서 c(construct)와 p(property)라는 네임스페이스를 이용하고 싶으면
// xmlns:c="http://www.springframework.org/schema/c"
// xmlns:p="http://www.springframework.org/schema/p"
// 이 두가지를 넣어주며 된다.  두 가지방법중  골라서 사용하면 된다.
​
===========================================================================================
​
// 마지막으로 MainClass.java 에서 어떻게 사용해야 하는지 보자!
package com.javalec.ex;
​
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.GenericXmlApplicationContext;
​
public class MainClass {
    public static void main(String[] args) {
        
        String configLog1 = "classpath:applicationCTX.xml";
        String configLog2 = "classpath:applicationCTX1.xml";
        
        //IOC 컨테이너에 두개의 컴포넌트를 삽입
        AbstractApplicationContext ctx = new GenericXmlApplicationContext(configLog1, configLog2);
        
        Student student1 = ctx.getBean("student1", Student.class);
        System.out.println(student1.getName());
        System.out.println(student1.getHobbys());
        
        // studentInfo 클래스의 getStudent를 이용하여 어떤것을 참조하는지 확인할 것(applicationCTX.xml에서!)
        StudentInfo studentInfo = ctx.getBean("studentInfo", StudentInfo.class);
        Student student2 = studentInfo.getStudent();
        System.out.println(student2.getName());
        System.out.println(student2.getHobbys());
        
        if(student1.equals(student2)) {
            System.out.println("student1 == student2");
        }
        
        Student student3 = ctx.getBean("student3", Student.class);
        
        if(student1.equals(student3)) {
            System.out.println("student1 == student3");
        } else {
            System.out.println("student1 != student3");
        }
        
        Family family = ctx.getBean("family", Family.class);
        System.out.println(family.getPapaName());
        System.out.println(family.getMamiName());
        System.out.println(family.getSisterName());
        System.out.println(family.getBrotherName());
        
        ctx.close();
    }
}
​
======결과======
홍길동
[게임, 산책, 운동]
홍길동
[게임, 산책, 운동]
student1 == student2
student1 != student3
홍아빠
홍엄마
홍스터
홍브라
​
====================================================================================
// StudentInfo 클래스를 깜빡했는데, 위에 결과가 나오기 위해선 getStudent()가 어떻게 작동하는지
// applicationCTX.xml 과 잘 생각하여 확인 !
​
package com.javalec.ex;
​
public class StudentInfo {
    
    Student student;
    
    public StudentInfo() {
        
    }
    
    public void setStudent(Student student) {
        this.student = student;
    }
    
    public Student getStudent() {
        return student;
    }
}
​