Spring 泛型依赖注入

Spring 泛型依赖注入，是利用泛型的优点对代码时行精简，将可重复使用的代码全部放到一个类之中，方便以后的维护和修改，同时在不增加代码的情况下增加代码的复用性。

示例代码：

1. 创建实体类
   Product

   
   package test.spring.model;
   
   public class Product {
   	private int id ;
   	private String name;
   	/* setter getter省略 */
   	@Override
   	public String toString() {
   		return "Product [id=" + id + ", name=" + name + "]";
   	}
   	
   }

   User

   package test.spring.model;
   
   public class User {
   	private int id;
   	private String name;
   
   	/* setter、getter省略 */
   
   	@Override
   	public String toString() {
   		return "User [id=" + id + ", name=" + name + "]";
   	}
   
   	public User() {
   		super();
   	}
   
   }

2. 创建Dao层相关接口及实现类
   
   对dao层的相同功能提取出来，创建一个带泛型的BaseDao类用于共用。

   package test.spring.Dao;
   
   import org.springframework.stereotype.Repository;
   
   /*必须加入注解，将BaseDao注入Spring容器，因为BaseService中有引用该类*/
   @Repository
   public class BaseDao<T> {
   	public void add(T t) {
   		System.out.println("BaseDao...."+t);
   	}
   
   }

   
   UserDao接口

   package test.spring.Dao;
   
   import test.spring.model.User;
   
   public interface UserDao {
   	public void add(User user);
   
   }
   

   UserDao实现类
    

   package test.spring.Dao;
   import org.springframework.stereotype.Repository;
   
   import test.spring.model.User;
   @Repository ("userDaoImpl")
   public class UserDaoImpl extends BaseDao<User> implements UserDao {
   
   }
   

   ProductDao接口
    

   package test.spring.Dao;
   
   import test.spring.model.Product;
   
   public interface ProductDao {
   	public void add(Product pro);
   }

   ProductDao实现类
    

   package test.spring.Dao;
   
   import org.springframework.stereotype.Repository;
   
   import test.spring.model.Product;
   @Repository("productDao")
   public class ProductDaoImpl extends BaseDao<Product> implements ProductDao {
   
   
   }

3. Spring配置

   <?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="test.spring" >	</context:component-scan>
   	
   </beans>

4. 测试

   package testSpring;
   
   import org.junit.Test;
   import org.springframework.context.ApplicationContext;
   import org.springframework.context.support.ClassPathXmlApplicationContext;
   
   import test.spring.model.Product;
   import test.spring.model.User;
   import test.spring.service.ProductService;
   import test.spring.service.UserService;
   
   public class TestSpring {
   	@Test
   	public void testUser() {
   		ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
   		
   		  UserService userService=(UserService) ac.getBean("userService");
   		  userService.add(new User());
   		 System.out.println("-----------------------------");
   		ProductService  proService= (ProductService) ac.getBean("prodcutService");
   		proService.add(new Product());
   
   	}
   }

   结果：