泛型依赖注入
看代码:
package logan.spring.study.generic.di; public class BaseRepository<T> { }
package logan.spring.study.generic.di; import org.springframework.beans.factory.annotation.Autowired; public class BaseService<T> { @Autowired protected BaseRepository<T> repository; public void add(){ System.out.println("add..."); System.out.println(repository); } }
package logan.spring.study.generic.di; import org.springframework.stereotype.Service; @Service public class UserService extends BaseService<User>{ }
package logan.spring.study.generic.di; public class User{ }
package logan.spring.study.generic.di; import org.springframework.stereotype.Repository; @Repository public class UserRepository extends BaseRepository<User>{ }
<?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-4.3.xsd"> <context:component-scan base-package="logan.spring.study.generic.di"></context:component-scan> </beans>
package logan.spring.study.generic.di; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Main { public static void main(String[] args) { // TODO Auto-generated method stub ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-generic.xml"); UserService userService = (UserService) ctx.getBean("userService"); userService.add(); } }
输出结果:
五月 27, 2017 2:04:02 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh 信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@42110406: startup date [Sat May 27 14:04:02 CST 2017]; root of context hierarchy 五月 27, 2017 2:04:02 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions 信息: Loading XML bean definitions from class path resource [beans-generic.xml] add... logan.spring.study.generic.di.UserRepository@43a0cee9