spring是咱們項目中常用的框架,spring中採用bean的方式注入能夠減小代碼。bean 的項目注入是項目中最基本的功能。java
在spring中的注入方式主要有三種。spring
1。java顯示注入框架
public class MusicConfig {
@Bean
public CompactDiscService setCompactDiscService(){
return new CompactDiscServiceImpl();
}ide
或者component
<?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:p="http://www.springframework.org/schema/p"
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-3.0.xsd">
<bean class="com.music.service.CompactDiscServiceImpl"></bean>
</beans>xml
}io
2.xml的顯示注入class
<?xml version="1.0" encoding="UTF-8"?>配置
<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:p="http://www.springframework.org/schema/p"
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-3.0.xsd">
<context:component-scan base-package="com.music"/>
</beans>coding
3.java 的隱式注入
1)在class中增長@compoment註解
@Component
public class CompactDiscServiceImpl implements CompactDiscService {
public void play() {
System.out.println("hello i go to study");
}
}
2)增長spring 掃描bean 的config
@Configuration
@ComponentScan
public class MusicConfig {
}
注 能夠採用@name的方式來替代@component的替代方案。
ComponentScan默認掃描@configuration目錄下的包,若是須要掃描多個包則配置@ComponentScan(basePackage={"system.com","video.com"})的方式就行註解便可