Spring4.x之泛型依赖注入

最新推荐文章于 2022-07-02 18:45:10 发布

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本文介绍如何在Spring4.x中实现泛型依赖注入，通过定义泛型基类和实现类，再借助Spring的组件扫描功能完成依赖注入过程。示例包括自定义的泛型基类`BaseRepository<T>`、泛型服务类`BaseService<T>`及其具体实现`ProductRepository`和`ProductService`。

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。

示例

1. 添加Java模型

package xyz.huning.spring4.di.annotation.beancfg.generic;

public class Product {

	private int id;

	private String name;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String toString() {
		return "Product [id=" + id + ", name=" + name + "]";
	}

}

package xyz.huning.spring4.di.annotation.beancfg.generic;

public class BaseReposity<T> {

	public void save()
	{
		System.out.println(this.getClass().getGenericSuperclass() + ": save operation.");
	}
	
}

package xyz.huning.spring4.di.annotation.beancfg.generic;

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

public class BaseService<T> {

	@Autowired
	protected BaseReposity<T> baseReposity;
	
	public void save()
	{
		baseReposity.save();
	}
}

package xyz.huning.spring4.di.annotation.beancfg.generic;

import org.springframework.stereotype.Repository;

@Repository
public class ProductReposity extends BaseReposity<Product>{

}

package xyz.huning.spring4.di.annotation.beancfg.generic;

import org.springframework.stereotype.Service;

@Service
public class ProductService extends BaseService<Product> {

}

2. 添加配置

<?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-4.0.xsd">
	
	<context:component-scan base-package="xyz.huning.spring4.di.annotation.beancfg.generic">
	</context:component-scan>
	
</beans>

3. 添加测试类

package xyz.huning.spring4.di.annotation.beancfg.generic;

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

public class Main {
	
    public static void main(String[] args) {
		
    	ApplicationContext context = new ClassPathXmlApplicationContext("generic-annotation.xml");
    	
    	ProductService productService = context.getBean("productService", ProductService.class);
    	productService.save();
    	
    	((ClassPathXmlApplicationContext)context).close();
    	
	}
}

4. 执行测试