注解开发
配置文件
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"><!-- 扫描指定包下的注解--> <context:component-scan base-package="com.spring"/><!-- 开启注解开发--> <context:annotation-config></context:annotation-config></beans>POJO
@Component//作为组件注入bean 相似于<bean id="user" class="com.spring.pojo.User"/>public class User { //值的注入相似于咱们的<property name="name" value="张三"></property> @Value("张三") private String name; public String getName() { return name; }}Dao
@Repository//注入默认为 Dao层对应三层架构的数据长久层public class UserDao { private User user; @Autowired public UserDao(User user){ this.user = user; } public void getName(){ System.out.println(user.getName()); }}Service
@Service//注入默认为 Service层对应三层架构的业务层public class UserService { public UserDao userDao; @Autowired public UserService(UserDao userDao){ this.userDao = userDao; } public void getName(){ userDao.getName(); }}Controller
@Controller//注入默认为 Controller层对应三层架构的管制层层public class UserController { private UserService userService; @Autowired public UserController(UserService userService){ this.userService=userService; } public void getName(){ userService.getName(); }}启动类
public class AnnotationTest { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml"); UserController userDao = context.getBean("userController", UserController.class); userDao.getName(); }}纯注解开发
配置文件
/*** 表明该类是Spring的配置类* 相似于咱们的xml文件* 这个类也会交给Spring治理,@Configuration蕴含@Component注解*/@Configuration/** * 包扫描相似于 <context:component-scan base-package="com.spring"/> */@ComponentScan("com.spring")/** * 导入另一个配置文件 * 相似于 <import resource="springConfig2.xml"></import> */@Import(SpringConfig2.class)public class SpringConfig { /** * 相似于<bean></bean> * 注入了一个对象 * 办法名是id属性 * 办法返回值的类型是class属性 */ @Bean public User user(){ return new User(); }}