Spring Annotation-Based Development and MyBatis Integration Tutorial

Spring 3.0 introduced pure annotation development, simplifying configuration and integrating tightly with MyBatis.

Annotations are special interfaces extending Annotation; at runtime they are implemented by dynamic proxy classes. Using @Component replaces XML <bean> definitions, and <context:component-scan> can be replaced by @ComponentScan in a @Configuration class.

Bean scopes are controlled with @Scope (singleton or prototype). Dependency injection is achieved with @Autowired, optionally qualified by @Qualifier to resolve multiple candidates. Simple value injection uses @Value, and external properties are loaded with @PropertySource and injected via @Value placeholders.

For MyBatis integration, add spring-jdbc and mybatis-spring dependencies, configure a DataSource, create a configuration class annotated with @Configuration, @ComponentScan and @Import, obtain SqlSessionFactory, and retrieve mapper beans from the ApplicationContext.

All code examples are shown below:

<bean id="a" class="yu7daily.Dao.Daoimpl.A"/>

@Component("a")
public class A implements AA {
    public void save() {
        System.out.println("book dao save ...");
    }
}

<context:component-scan base-package="yu7daily.Dao"/>

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
A aa = (A) ctx.getBean("a");
bookService.save();

@Qualifier("a")
private AA aa;

@Value("${name}")
private String str;

@Configuration
@ComponentScan("yu7daily")
@PropertySource("test.properties")
public class SpringConfig { ... }

ApplicationContext ACC = new AnnotationConfigApplicationContext(SpringConfig.class);
AccountService acc = ACC.getBean(AccountService.class);