Spring是分层的Java SE/EE应用全栈(full-stack)轻量级开发框架,以IoC(Inverse of Control:反转控制)和AOP(Aspect Oriented Programing:面向切面编程)为内核
提供了展现层(Spring MVC)和持久层Spring JDBCTemplate以及业务层事务管理等众多企业级应用技术,还能整合开源世界众多著名的第三方框架和类库,逐渐成为使用最多的Java EE企业应用开发框架
在我们之前的开发步骤中,Dao层的对象需要我们自行创建,这就导致程序耦合较高,通关Spring我们可以将Dao层路径定义在XML配置文件中,再利用Spring通关反射创建该对象,以实现程序的解耦
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.3.3</version>
</dependency>
</dependencies>
Dao接口
package cn.ywrby.dao;
public interface UserDao {
public void save();
}
实现类
package cn.ywrby.dao.impl;
import cn.ywrby.dao.UserDao;
public class UserDaoImpl implements UserDao {
public void save() {
System.out.println("Save Running...");
}
}
一般命名为applicationContext.xml,保存在resources文件夹内(创建时直接利用Spring Config模板创建即可)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
</beans>
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="userDao" class="cn.ywrby.dao.impl.UserDaoImpl"></bean>
</beans>
public class UserDaoDemo {
public static void main(String[] args) {
ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
UserDao dao= (UserDao) context.getBean("userDao");
dao.save();
}
}