service层
要调用 dao层
,为了解耦使用 xml 配置文件,简单地说 spring 就是读取配置文件的,通过 spring客户端的 getBean
方法传入 id 标识就可以获得对象,这样就实现了解耦
```xml
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.0.5.RELEASE</version>
</dependency>
```
UserDao.java
```java
package com.ruochen.dao;
public interface UserDao {
public void save();
}
```
- 实现类:`UserDaoImpl.java`
```java
package com.ruochen.dao.impl;
import com.ruochen.dao.UserDao;
public class UserDaoImpl implements UserDao {
@Override
public void save() {
System.out.println("save running...");
}
}
```
resources/applicationContext.xml
```xml
<?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="com.ruochen.dao.impl.UserDaoImpl"></bean>
</beans>
```
UserDaoDemo.java
```java
package com.ruochen.demo;
import com.ruochen.dao.UserDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class UserDaoDemo {
public static void main(String[] args) {
ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
UserDao userDao = (UserDao) app.getBean("userDao");
userDao.save();
}
}
```
save running...
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
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原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。