Spring使用IOC与DI实现完全注解开发

 <dependencies>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.20</version>
    </dependency>
    <dependency>
      <groupId>javax.annotation</groupId>
      <artifactId>javax.annotation-api</artifactId>
      <version>1.3.2</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

package com.szh.bean;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Data
@Component
public class Student {
    @Value("张起灵")
    private String name;
    @Value("20")
    private Integer age;
    @Autowired
    private School school;
}

package com.szh.bean;
import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Data
@Component
public class School {
    @Value("北京大学")
    private String name;
    @Value("北京市海淀区")
    private String address;
}

package com.szh.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages = "com.szh.bean")
public class SprinGConfig {
}

package com.szh;
import com.szh.bean.Student;
import com.szh.config.SpringConfig;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class MyTest {
    @Test
    public void testIocAnnotation() {
        ApplicationContext ioc = new AnnotationConfigApplicationContext(SpringConfig.class);
        Student student = (Student) ioc.getBean("student");
        System.out.println(student);
    }
}

package com.szh.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Goods {
    private String name;
    private String info;
}

package com.szh.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.math.BigDecimal;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Order {
    private Integer id;
    private BigDecimal totalFee;
    private Goods goods;
}

package com.szh.config;
import com.szh.entity.Goods;
import com.szh.entity.Order;
import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.math.BigDecimal;

@Configuration
public class SpringConfig2 {
    @Bean
    public Goods goods() {
        return new Goods("联想-拯救者", "一款不错的游戏笔记本");
    }
    @Bean
    public Order order(Goods goods) {
        return new Order(1, new BigDecimal(9999), goods);
    }
}

    @Test
    public void testIocAnnotation2() {
        ApplicationContext ioc = new AnnotationConfigApplicationContext(SpringConfig2.class);
        Order order = (Order) ioc.getBean("order");
        System.out.println(order);
        System.out.println("IOC容器中存在的bean如下：");
        String[] beanDefinitionNames = ioc.getBeanDefinitionNames();
        for (String bean : beanDefinitionNames) {
            System.out.println(bean);
        }
    }