一文掌握Spring的创建与使用

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.20</version>
        </dependency>
 
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.3.20</version>
        </dependency>
 
 
    </dependencies>

public class App {
    public static void main(String[] args) {
        System.out.println("Hello Spring");
    }
}

<?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">
</beans>

  <bean id="user" class="com.spring.demo.Bean.User"></bean>

//获取Spring上下文
ApplicationContext context=new ClassPathXmlApplicationContext("spring-config.xml");

//获取指定Bean对象
User user = (User)context.getBean("user");

public static void main(String[] args) {
        //获取Spring上下文
        BeanFactory beanFactory=new XmlBeanFactory(new ClassPathResource("spring-config.xml"));
        //获取Bean对象
        User user= (User) beanFactory.getBean("user");
        //使用bean
        user.sayHi();
    }

User user = (User)context.getBean("user");

User user1 = context.getBean(User.class);

User user2 = context.getBean("user",User.class);