在父類中建立關系 (spring4.x以上版本)

package com.spring.annotation.generic;

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

public class BaseService<T> {

    @Autowired
    private BaseRepository<T> dao;
    
    public void add(T entity){
        System.out.println("add by " + dao);
        dao.save(entity);
    }
    
}



 
package com.spring.annotation.generic;

public class BaseRepository<T> {

    public void save(T entity){
        System.out.println("save:" + entity);
    }
    
}

子類

package com.spring.annotation.generic;

import org.springframework.stereotype.Service;

@Service
public class UserService extends
 
 BaseService<User>{

}


package com.spring.annotation.generic;

import org.springframework.stereotype.Repository;

@Repository
public class UserDao extends BaseRepository<User>{

}

測試

package com.spring.annotation.generic;

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-annotation.xml");
        
        UserService userService = (UserService) ctx.getBean("userService");
        userService.add(new User());
        
        
    }
    
}

結果

Sprinig泛型依賴註入