[Spring] DI_2

DI_2

1. Bean 정의 파일로 DI

1_1. BeanFactory

- DI 컨테이너의 핵심이 됨

- BeanFactory는 실행 시에 건네지는 Bean정의 파일(applicationContext.xml)을 바탕으로 인스턴스를 생성하고 인젝션한다

- 웹 어플리케이션 개발에 개발자가 직접 이용하는 일은 별로 없다

- ClassPathXmlApplicationContext는 BeanFactory의 상위에 있다

- BeanFactory의 이용

BeanFactory beanFactory = new ClassPathXmlApplicationContext("applicationContext.xml");

1) Bean정의 파일

- Bean의 정의 파일을 프로퍼티, xml, LDAP 등으로 다루지만 XML이 일반적이다

- Bean정의 파일 이용시 Setter 메소드가 필요하다

- applicationContext.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <bean id="productService" class="DI.service.ProductServiceImpl" autowire="byType"/> <bean id="productDao" class="DI.dao.ProductDaoImpl"/> </beans>

- ProductServiceImpl

package DI.service; import DI.dao.ProductDao; import DI.domain.Product; public class ProductServiceImpl implements ProductService{ private ProductDao productDao; public Product findProduct(String name){ return productDao.findProduct(name); } public void setProductDao(ProductDao productDao){ this.productDao = productDao; } }

2) Bean 정의 파일 분할

- 규모가 커질수록 빈 정의 파일을 분할 하는게 좋다

- applicationContext.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${jdbc.driverClass}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </bean> </beans>

- applicationContext-bean.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <bean id="productService" class="DI.service.ProductServiceImpl" autowire="byType"/> <bean id="productDao" class="DI.dao.ProductDaoImpl"/> </beans>

- import.xml

<beans> <import resource="config/services.xml"/> <import resource="resources/dataaccess.xml"/> </beans>

3)  프로퍼티 파일 이용

a.  bean정의 파일 경우

- message.properties

message = "Hello Spring"

- applicationContext.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-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <util:properties id="msgProperties" location="classpath:DI/properties/message.properties"/> <bean id="message" class="sample.MessageServiceImpl"> <property name="message" value="#{msgProperties.message}"/> </bean> </beans>

- MessageServiceImpl

package DI.service; public class MessageServiceImpl implements MessageService{ private String message; public void setMessage(String message){ this.message = message; } public String getMessage(){ return message; } }

b. annotation  경우

- applicationContext.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-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <context:annotation-config/> <context:component-scan base-package="DI.*"/> <util:properties id="msgProperties" location="classpath:DI/properties/message.properties"/> </beans>

- MessageServiceImpl

package DI.service; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Component; @Component public class MessageServiceImpl implements MessageService{ @Value("#{msgProperties.message") private String message; public String getMessage(){ return message; } }

2. ApplicationContext

- ApplicationContext 는  BeanFactory를 확장해 Bean 정의파일 읽기, 메세지 소스, 이벤트 처리 등의 기능을 추가한것이다

2_1. Bean 정의 파일 읽기

- 웹 어플리케이션은  ContextLoaderListener 클래스나  ContextLoaderServlet 클래스에 의해 자동으로 ApplicationContext(XmlWebApplicationContext 클래스)가 로드됨

a. web.xml

<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- Listener를 사용 할수 없을시 <servlet> <servlet-name>context</servlet-name> <servlet-class>org.springframework.web.context.ContextLoaderServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> --> </web-app>

b. 복수의  Bean 정의 파일

<context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml / WEB-INF/applicationContext-persist.xml</param-value> </context-param>

c. 웹 어플리케이션에선 ApplicationContext를 클래스에서 직접 이용할 일이 없지만 간단한 예제 어플리케이션을 만들때는 아래처럼 사용한다

    ApplicationContext context = new ClassPathXmlApplicationContext("a.xml","b.xml","c.xml");

d. ApplicationContext를 POJO로 만들어진 클래스에 직접 이용할떄

- @Autowired를 사용

@Component public class ProductServiceImpl implements ProductService{ private ProductDao productDao; @Autowired private ApplicationContext ac; public Product findProduct(String name){ productDao = (ProductDao) ac.getBean("/DI/dao/ProductDaoImpl.class"); return productDao.findProduct(name); } }

3. Spring logging

- 스프링은 기본적으로 Commons Logging으로 로그를 출력함

- Log4j라이브러리가 있으면 Commons Logging이 Log4j를 사용한다

- WEB-INF 또는 클래스 패스 아래에 두면 사용가능하다

- log4j.xml

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> <appender name="stdout" class="org.apache.log4j.ConsoleAppender"> <layout class="org.apahce.log4j.PatternLayout"> <param name="ConversionPattern" value="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> </layout> </appender> <logger name="org.springframework.beans"> <level value="debug"/> </logger> <logger name="org.springframework.transaction"> <level value="debug"/> </logger> <root> <priority value="error"/> <appender-ref ref="stdout"/> </root> </log4j:configuration>

4. Spring unitTest

- DI 컨테이너로 관리하는 오브젝트를 유닛 테스트하기 위한 기능이 제공됨

- Test.java

package DI.test; import org.junit.Test; import org.junit.runner.RunWith; import static org.hamcrest.CoreMatchers.is; import static org.junit.Assert.*; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import DI.domain.Product; import DI.service.ProductService; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations={"../applicationContext.xml"}) public class ProductServiceTest { @Autowired ProductService productService; @Test public void testFindProduct(){ Product product = productService.findProduct("Kyle"); assertEquals(new Product("Kyle",100),product); } }

- 데이터 베이스 테스트시 자바의 내장 데이터베이스를 사용한다