bean配置类的注解开发
问题提出
用类充当配置文件 applicationcontext.xml :
@Configuration注解标识此类为配置类,替代原有xml文件
看原配置文件applicationcontext.xml代码
<?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.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!--注解组件扫描: 扫描的指定基本包及其包下的类,识别使用@component注解-->
<context:component-scan base-package="com.itheima"/>
<context:property-placeholder location="classpath:jdbc.properties"/>
</beans>这是bean配置类的文件SpringConfig(Java文件)
package com.itheima.config;
import com.itheima.beans.OtherBean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.PropertySource;
@Configuration //标注当前类是一个配置类(替代配置文件) +@Component
//<context:component-scan base-package="com.itheima"/> 配置组件扫描
@ComponentScan({"com.itheima"})
//<context:property-placeholder location="classpath:jdbc.properties"/> 配置properties加载
@PropertySource("classpath:jdbc.properties")
//<import resource=""></import>
@Import(OtherBean.class)
public class SpringConfig {
}
@ComponentScan({"com.itheima"})
组件扫描配置:扫描包
@PropertySource("classpath:jdbc.properties")
加载外部资源properties
@Import(OtherBean.class)
导入其他配置类
