spring 泛型

Spring4.0可以为子类注入子类的泛型类型，成员变量的引用
BaseService<T>:有RoleService和UserService两的子类
BaseRepepositry<T>:有UserRepository和RoleRepositry两个子类

因为BaseService<T>继承 BaseRepepositry<T> ，得出下面的子类也存在这样的关系
代码：
User.java

public class User {

}

BaseService.java

import org.springframework.beans.factory.annotation.Autowired;

public class BaseService<T> {
	 @Autowired
	 protected BaseRepository<T> repository;
	 
	 public void add(){
		 
		 System.out.println("adding....");
		 System.out.println(repository);	 
	 }
}

UserService.java

import org.springframework.stereotype.Repository;

@Repository 
public class UserService extends BaseService<User>{

}

BaseRepository.java

public class BaseRepository<T> {}

UserRepository.java

import org.springframework.stereotype.Repository; 
 @Repository   //交给IOC容器来管理
public class UserRepository extends BaseRepository<User>{}

Main.java

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {

    public static void main(String[] args) {
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext(
                 "applicationContext.xml");
 
        UserService userService = (UserService) applicationContext.getBean("userService");
 
        userService.add();
    
     }
}

输出结果：

adding....
com.spring.txing.UserRepository@7174d93a