SPRING框架2

注解开发定义bean

　　使用@Component定义bean

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@Component("bookDao") public class BookDaoImpl implements BookDao {       @Override     public void find() {         System.out.println("BookDaoImpl...");     } }

　　核心配置文件中通过组件扫描加载bean

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1	<context:component-scan base-package="com.itcast"></context:component-scan>

　　spring提供@Component注解的三个衍生注解

• @Controller：用于表现层bean定义
• @Service：用于业务层bean定义
• @Repository：用于数据层bean定义

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@Repository("bookDao") public class BookDaoImpl implements BookDao {} @Service public class BookServiceImpl implements BookService {}

　　

纯注解开发

 

 

 

 

bean的生命周期

 

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@Repository @Scope("singleton") public class BookDaoImpl implements BookDao {}

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@Repository("bookDao") @Scope("singleton") public class BookDaoImpl implements BookDao {     @Override     public void save() {         System.out.println("book dao save...");     }       @PostConstruct     public void init() {         System.out.println("初始化。。");     }       @PreDestroy     public void destroy() {         System.out.println("销毁。。。");     } }<br><br><br><br>//关闭容器

ctx.close

依赖注入

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@Service public class BookServiceImpl implements BookService {     @Autowired     private BookDao bookDao; //可省略setter方法 //    public void setBookDao(BookDao bookDao) {         this.bookDao = bookDao;         }     public void save() {         System.out.println("book service save ...");         bookDao.save();     } }

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@Service public class BookServiceImpl implements BookService {     @Autowired     @Qualifier("bookDao")     private BookDao bookDao; }

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@Repository("bookDao") public class BookDaoImpl implements BookDao {     @Value("itheima")     private String name; }

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@Configuration @ComponentScan("com.itheima") @PropertySource("classpath:jdbc.properties") public class SpringConfig {}

 第三方bean管理

 

 

 

 

 

 

 XML配置比对注解配置