spring4.x 新特性-泛型依赖注入
一:泛型依赖注入
1.spring 4.x中可以为子类注入子类对应得泛型类型的成员变量的引用
二.代码实现
1.创建一个泛型的BaseRepository类
package com.dhx.generic.di;
public class BaseRepository<T> {
}
2.创建一个泛型的BaseService,并配置与BaseRepository之间的关系
package com.dhx.generic.di;
import org.springframework.beans.factory.annotation.Autowired;
public class BaseService<T> {
@Autowired //子类会继承这种关联关系
protected BaseRepository<T> repository;
public void add() {
System.out.println("add...");
System.out.println(repository);
}
}
3.创建一个user类
package com.dhx.generic.di;
public class User {
}
4.创建一个UserRepository并继承BaseRepository类
package com.dhx.generic.di;
import org.springframework.stereotype.Repository;
@Repository
public class UserRepository extends BaseRepository<User>{
}
5.创建一个UserService并继承BaseService类
package com.dhx.generic.di;
import org.springframework.stereotype.Service;
@Service
public class UserService extends BaseService<User>{
}
6.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-4.0.xsd">
<context:component-scan base-package="com.dhx.generic.di"></context:component-scan>
</beans>
7.测试
package com.dhx.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("beans-generic-di.xml");
UserService userService=(UserService) ctx.getBean("userService");
userService.add();
}
}