15Spring泛型依赖注入

Spring 4.x中可以为子类注入子类对应的泛型类型的成员变量的引用

BaseService<T>:有RoleService和UserService两的子类

BaseRepepositry<T>:有UserRepository和RoleRepositry两个子类

由于 BaseService<T>和 BaseRepepositry<T> 有关系所以，得出下面的子类也存在这样的关系

package generic.di; 

public class BaseRepository<T> { } 

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package 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 generic.di;

import org.springframework.stereotype.Repository;

@Repository
public class RoleRepository extends BaseRepository<Organization> {
}
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package generic.di;
import org.springframework.stereotype.Service;

@Service
public class RoleService extends BaseService<Organization> {
}
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package generic.di;

public class Organization {
}

package generic.di;

public class User {
}
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package generic.di;

import org.springframework.stereotype.Repository;

@Repository
public class UserRepository extends BaseRepository<User> {

}

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package generic.di;

import org.springframework.stereotype.Service;

@Service
public class UserService extends BaseService<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.xsd">
       <context:component-scan base-package="generic.di">
       </context:component-scan>
</beans>

package generic.di;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("generic/di/15-1.xml");
        UserService userService = (UserService) ctx.getBean("userService");
        RoleService roleService = (RoleService) ctx.getBean("roleService");
        userService.add();
        roleService.add();
    }
}