<beans xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xmlns:aop="http://www.springframework.org/schema/aop"

    xmlns:context="http://www.springframework.org/schema/context"

    xsi:schemaLocation="

       http://www.springframework.org/schema/beans

       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

       http://www.springframework.org/schema/aop

       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd

       http://www.springframework.org/schema/context

       http://www.springframework.org/schema/context/spring-context-3.0.xsd"

        >

    <!-- component-scan 会自动开启bean自动注册,base-package会扫描该包下的特殊注解 -->

    <context:component-scan base-package="com.donghai.bean" />

</beans>

package com.donghai.bean;

import org.springframework.stereotype.Component;

@Component("user") //使用Component注解,相当于添加<bean id="user" class="com.donghai.bean.User" />

public class User {

    private String name = "ddh";

    public String getName() {

        return name;

    }

}

package com.donghai.bean;

import javax.annotation.Resource;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Component;

@Component("group")

public class Group {

    @Autowired  //使用自动装配,默认按照byType对应的类型查找bean,如果只有一个注入,如果有多个抛出异常
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type
需要使用@Qualifier(" ") 来指定使用那个实现
,也可以使用Resource(name="user") 使用资源指定

    private User user;

    public User getUser() {

        return user;

    }

}

package com.donghai.spring;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.donghai.bean.Group;

import com.donghai.bean.User;

public class Client {

    public static void main(String[] args){

        ApplicationContext acc = new ClassPathXmlApplicationContext("applicationContext.xml");

        Group group = (Group)acc.getBean("group");

        System.out.println(group.getUser().getName());

    }

}