Spring注解系列二十：自动装配-@Resource

梦里梦外; 2022-01-23 04:25 295阅读 0赞

Spring还支持使用@Resource(JSR250)和@Inject(JSR330)\[java规范的注解\]  
一、@Resource:  
 可以和@Autowired一样实现自动装配功能；默认是按照组件名称进行装配的。  
 不能支持@Primary功能，不能支持@Autowired（reqiured=false）。  
1、BookDao

@Repository
    public class BookDao {
    
        private String lable = "1";
    
        public String getLable() {
            return lable;
        }
    
        public void setLable(String lable) {
            this.lable = lable;
        }
    
        @Override
        public String toString() {
            return "BookDao [lable=" + lable + "]";
        }
    
    }

2、MainConifgOfAutowired

@Configuration
    @ComponentScan({"com.atguigu.service","com.atguigu.dao"})
    public class MainConifgOfAutowired {
    
    	@Primary
    	@Bean("bookDao2")
    	public BookDao bookDao(){
    		BookDao bookDao = new BookDao();
    		bookDao.setLable("2");
    		return bookDao;
    	}
    }

3、BookService

@Service
    public class BookService {
        
        @Resource
        private BookDao bookDao;
    
        @Override
        public String toString() {
            return "BookService{" +
                    "bookDao=" + bookDao +
                    '}';
        }
    }

测试：

@Test
    public void test01(){
    	AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConifgOfAutowired.class);
    	
    	BookService bookService = applicationContext.getBean(BookService.class);
    	System.out.println(bookService);
    
    	BookDao bean = applicationContext.getBean(BookDao.class);
    	System.out.println(bean);
    
    	applicationContext.close();
    }

![在这里插入图片描述][20190602121717565.png]  
修改BookService，使用@Resource(name = “bookDao2”)指定bean的名称

@Service
    public class BookService {
    
        @Resource(name = "bookDao2")
        private BookDao bookDao;
    
        @Override
        public String toString() {
            return "BookService{" +
                    "bookDao=" + bookDao +
                    '}';
        }
    }

![在这里插入图片描述][20190602121919270.png]  
二、@Inject:  
 需要导入javax.inject的包，和Autowired的功能一样。没有属性，不能支持required=false的功能。  
1、引入依赖

<dependency>
    	<groupId>javax.inject</groupId>
    	<artifactId>javax.inject</artifactId>
    	<version>1</version>
    </dependency>

2、修改BookService使用 @Inject 注解

@Service
    public class BookService {
    
        @Inject
        private BookDao bookDao;
    
        @Override
        public String toString() {
            return "BookService{" +
                    "bookDao=" + bookDao +
                    '}';
        }
    }

![在这里插入图片描述][20190602122513217.png]  
@Autowired：Spring定义的； @Resource、@Inject都是java规范。  
AutowiredAnnotationBeanPostProcessor：解析完成自动装配功能。

[20190602121717565.png]: /images/20220123/ff080ca3dea74da099debad933a9f26e.png
[20190602121919270.png]: /images/20220123/c7219f8b3a3347c5b49034e8d79eeadc.png
[20190602122513217.png]: /images/20220123/1f5f3274421c46a593c052a9ff1cf07f.png