Spring_Bean에 값 세팅

💡 매개변수에 따라 Bean에 값 넣기

클래스 생성자의 매개변수 개수가 동일하면 어디에 값을 넣게될까?

↓ 샘플 클래스

public class SampleBean5 {

	int num;
	String str;
	
	public SampleBean5() {
		num = 0;
		str = null;
	}
	
	public SampleBean5(int num) {
		this.num = num;
		this.str = null;
	}
	
	public SampleBean5(String str) {
		this.num = 0;
		this.str = str;
	}
	
	public SampleBean5(int num, String str) {
		this.num = num;
		this.str = str;
	}
	
	public int getNum() {
		return num;
	}
	
	public void setNum(int num) {
		this.num = num;
	}
	
	public String getStr() {
		return str;
	}
	
	public void setStr(String str) {
		this.str = str;
	}
	
}

>>> 생성자 중 각각 int num과 String str을 매개변수로 받는 클래스가 있음

<bean id="sampleBean5_2" class="com.app.beans.SampleBean5">
	<constructor-arg value="30"></constructor-arg>
</bean>

>>> 30이라는 값을 넣어봄

@RequestMapping("/sb5")
public String sb5() {
		
	SampleBean5 sb5 = (SampleBean5)applicationContext.getBean("sampleBean5_2");
	System.out.println(sb5.getNum());
	System.out.println(sb5.getStr());
		
	return "checkBean";
}

>>> 컨트롤러를 통해 출력 결과를 확인하고자함!

↓ 출력결과

>>> String이 우선순위로 잡혀 str 변수에 값이 들어간 것을 볼 수 있음!

매개변수에 따라 다르게 값을 넣어보자!

<!-- type으로 지정 -->
<bean id="sampleBean5_2" class="com.app.beans.SampleBean5">
	<constructor-arg value="30" type="int"></constructor-arg>
</bean>

<!-- value 값을 두 개 넣으면 두개의 매개변수로 지정 -->
<bean id="sampleBean5_3" class="com.app.beans.SampleBean5">
	<constructor-arg value="10"></constructor-arg>
	<constructor-arg value="20"></constructor-arg>
</bean>

↓ 컨트롤러

@RequestMapping("/sb5")
public String sb5() {
		
	SampleBean5 sb5 = (SampleBean5)applicationContext.getBean("sampleBean5_2");
	System.out.println(sb5.getNum());
	System.out.println(sb5.getStr());
		
	SampleBean5 sb5_2 = (SampleBean5)applicationContext.getBean("sampleBean5_3");
	System.out.println(sb5_2.getNum());
	System.out.println(sb5_2.getStr());
		
	return "checkBean";
}

↓ 출력결과

---

💡 Getter&Setter로 값 넣기

↓ GetSetBean.java 클래스

public class GetSetBean {
	
	int var1;
	String var2;
	String var3;
    
	// getter setter는 반드시 기본형 이름이어야 함!
	public int getVar1() {
		return var1;
	}
	public void setVar1(int var1) {
		this.var1 = var1;
	}
	public String getVar2() {
		return var2;
	}
	public void setVar2(String var2) {
		this.var2 = var2;
	}
	public String getVar3() {
		return var3;
	}
	public void setVar3(String var3) {
		this.var3 = var3;
	}
    @Override
	public String toString() {
		return "GetSetBean [var1=" + var1 + ", var2=" + var2 + ", var3=" + var3 + "]";
	}

}

↓ root-context.xml

<!-- Setter를 통한 주입 -->
<bean id="gsb1" class="com.app.beans.GetSetBean">
	<property name="var1" value="500"></property>
	<property name="var2" value="600"></property>
	<property name="var3" value="문자"></property>
</bean>

>>> property 태그 사용

↓ 컨트롤러

@RequestMapping("/getset")
public String getset() {
	GetSetBean gsb = (GetSetBean)applicationContext.getBean("gsb1");
	System.out.println(gsb.toString());
		
	return "checkBean";
}

↓ 출력결과

---

💡 Getter&Setter로 객체 넣기

↓ GetSetBean2.java 클래스

public class GetSetBean2 {
	//기본타입3개 + 객체타입 2개
	int var1;
	String var2;
	String var3;
	SampleBean1 sb1;
	SampleBean1 sb2;
	
	public int getVar1() {
		return var1;
	}
	public void setVar1(int var1) {
		this.var1 = var1;
	}
	public String getVar2() {
		return var2;
	}
	public void setVar2(String var2) {
		this.var2 = var2;
	}
	public String getVar3() {
		return var3;
	}
	public void setVar3(String var3) {
		this.var3 = var3;
	}
	public SampleBean1 getSb1() {
		return sb1;
	}
	public void setSb1(SampleBean1 sb1) {
		this.sb1 = sb1;
	}
	public SampleBean1 getSb2() {
		return sb2;
	}
	public void setSb2(SampleBean1 sb2) {
		this.sb2 = sb2;
	}
	@Override
	public String toString() {
		return "GetSetBean2 [var1=" + var1 + ", var2=" + var2 + ", var3=" + var3 + ", sb1=" + sb1 + ", sb2=" + sb2
				+ "]";
	}

}

↓ root-context.xml

<bean id="sb1" class="com.app.beans.SampleBean1"/>
<bean id="sb2" class="com.app.beans.SampleBean1"/>
	
<bean id="gsb2" class="com.app.beans.GetSetBean2">
	<property name="var1" value="500"></property>
	<property name="var2" value="600"></property>
	<property name="var3" value="문자"></property>
	<property name="sb1" ref="sb1"></property>
	<property name="sb2" ref="sb2"></property>
</bean>

<!-- ref=""로 객체를 부를 수 있지만, property 태그 안에 bean 태그를 넣어 코드를 간소화할 수 있음! -->
<!-- 
	<property name="sb1">
		<bean class="com.app.beans.SampleBean1"/>
	</property>
-->

↓ 컨트롤러

@RequestMapping("/getset")
public String getset() {
	GetSetBean gsb = (GetSetBean)applicationContext.getBean("gsb1");
	System.out.println(gsb.toString());
		
	GetSetBean2 gsb2 = (GetSetBean2)applicationContext.getBean("gsb2");
	System.out.println(gsb2.toString());
		
	return "checkBean";
}

↓ 출력결과